Lung Cancer Screening PCAs

Lung Cancer Screening PCAs. In this study, only 9.2% of individuals met the 2021 USPSTF lung cancer screening eligibility criteria. Among male patients with lung cancer, 23.2% were <50 years of age. In female patients with lung cancer, 33.3% were <50 years of age [35]. This study suggests that further evaluation of screening may be warranted in younger individuals, although more research is needed to assess the utility of screening in this population. Several studies have evaluated LDCT in patients with occupational exposures. In a cohort of 2,433 men exposed to asbestos, both lung cancer-related mortality and all-cause mortality was reduced amongst participants who underwent lung cancer screening [36]. A separate cohort study of LDCT among 7,189 nuclear weapons workers also demonstrated favorable results, detecting 80 lung cancers, of which 59% were stage I and an additional 10% were stage II [37]. As with the populations above, additional investigation is needed to assess screening in individuals with occupational exposures. FDG-PET/CT Skull Base to Mid-Thigh There is no evidence to support screening in this population with FDG-PET/CT. MRI Chest Without and With IV Contrast There is no evidence to support screening in this population with MRI chest without and with IV contrast. MRI Chest Without IV Contrast There is no evidence to support screening in this population with MRI chest without IV contrast. Radiography Chest There is no evidence to support screening in this population with chest radiography. Variant 3: Lung cancer screening. Patient of any age with less than 20 packs per year history of smoking, and no additional risk factor (ie, radon exposure or occupational exposure or cancer history or family history of lung cancer or history of COPD or history of pulmonary fibrosis). Initial imaging. CT Chest With IV Contrast There is no evidence to support screening in this population with chest CT with IV contrast. Lung Cancer Screening


Lung Cancer Screening PCAs

Lung Cancer Screening PCAs. CT Chest Without and With IV Contrast There is no evidence to support screening in this population with chest CT without and with IV contrast. CT Chest Without IV Contrast Screening Screening for lung cancer is routinely performed with noncontrast LDCT in individuals who are eligible based on age and smoking history. LDCT for lung cancer screening is not currently useful for those without a significant smoking history. A retrospective study of 28,807 patients that included 12,176 who had not smoked; however, showed that LDCT helped to detect a significant number of lung cancers suggesting that more study is needed to evaluate screening in this population [38]. This study and others are part of a growing body of literature evaluating the use of lung cancer screening in patients without a history of smoking. In South Korea, 37,436 asymptomatic adults (17,968 without a smoking history and 19,468 with a smoking history) were screened for lung cancer using LDCT. The lung cancer rate was lower in those who had not smoked; however, no significant differences were seen in the number of false positives or the complication rates between the 2 groups [39]. There is particular interest in evaluating lung cancer in women, because the incidence of lung cancer in women without a significant smoking history is greater than in men [40,41]. In a retrospective study of 2,170 patients in the UK with lung cancer, the annual frequency of lung cancer development in those without a smoking history increased from 13% to 28%. Of those patients with lung cancer who had not smoked, 67% were women [42]. In a real-world cohort study of lung cancer screening in China, a total of 15,996 participants underwent LDCT. Among male patients with lung cancer in this study, 75% had a history of tobacco use. Among female patients with lung cancer in this cohort, only 5.8% reported a history of smoking [35].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix.  Discussion of Procedures by Variant Variant 1: Initial local staging of pretreatment cervical cancer; assessment of local tumor extension (T staging) for any clinically visible lesion. Imaging is recommended for staging evaluation in any person with a clinically visible tumor or a microscopic tumor that is found to have >5 mm of invasion on biopsy, corresponding to stage 1B or greater disease [2]. Accurate determination of the size and local extent of the tumor is critical because this determines the treatment strategy used. Definitive surgery with radical hysterectomy with lymph node sampling is the treatment of choice for smaller (<4 cm), locally confined invasive cervical cancers (within the cervix or invading only the upper two-thirds of the vagina): stages IA2, IB1, IB2, and IIA1 [2]. Alternatively, trachelectomy can be considered for patients with stage IA2 or IB1 tumors who wish to maintain fertility. In this procedure, the cervix, parametrium, and vaginal cuff are removed with pelvic sentinel node biopsy or lymphadenectomy, and a cerclage suture is placed around the uterine isthmus to preserve uterine competency. Tumor size and location are critical factors in the assessment of trachelectomy candidacy, with cervix-confined tumors <2 cm in size and located >1 cm from the internal cervical os considered ideal features. Some centers will consider trachelectomy for patients with tumors <4 cm or as close to 0.5 cm from the internal os [7,8]. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Follow-up of Invasive Cancer of the Cervix In contrast, primary chemoradiotherapy is the treatment of choice for larger invasive cervical cancers (>4 cm) given their high likelihood of occult nodal metastases, locally advanced tumors invading the parametrium, lower one- third of the vagina, or adjacent pelvic organs, or those with known nodal or distant metastases (stages IB3, IIA2, IIB, III, and IVA, respectively) [2]. In this population, pretreatment imaging plays a critical role in radiation therapy treatment planning, specifically for contouring of the radiation field. CT Pelvis With IV Contrast Compared to MRI, CT provides very poor soft tissue characterization in the pelvis and therefore demonstrates a lower accuracy for the determination of local extent of invasive cervical cancer [9]. One multicenter study found that invasive cervical cancers, which appeared hypodense to the normal cervical stroma, were only well delineated in 35% to 73% of contrast-enhanced CT examinations [10]. Considering individual features, meta-analyses have shown CT with intravenous (IV) contrast to have 43% to 55% sensitivity and 71% specificity for parametrial invasion, and 41% sensitivity and 92% specificity for bladder invasion [11,12]. In comparison, MRI demonstrated 71% specificity (95% confidence interval [CI], 62%-79%) and 91% sensitivity (95% CI, 88%-93%) for parametrial invasion, and 84% sensitivity (95% CI, 57%-95%) and 95% specificity (95% CI, 87%-98%) for bladder invasion [12]. CT Pelvis Without and With IV Contrast CT pelvis without IV contrast provides very poor soft tissue characterization in the pelvis [13] and therefore is not useful for the evaluation of the local extent of invasive cervical cancer. The addition of noncontrast CT images would not appreciably add information to the contrast-enhanced CT evaluation.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. CT Pelvis Without IV Contrast CT without IV contrast provides very poor soft tissue characterization in the pelvis [13] and therefore is not useful for the evaluation of local extent of invasive cervical cancer. FDG-PET/CT Skull Base to Mid-Thigh Fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT is most commonly used in addition to pelvic MRI for nodal and metastatic disease assessment (as described in Variant 2), although it can also contribute to the evaluation of local disease extent. Physiologic excreted radiotracer in the bladder may obscure FDG uptake in the region of the cervix in some patients [9]. However, a meta-analysis showed similar overall diagnostic performance for PET/CT and MRI for local extent of disease assessment, with an overall sensitivity of 73% (95% CI, 56%-85%) and specificity of 91% (95% CI, 83%-96%) for PET/CT compared to a sensitivity of 71% (95% CI, 62%-79%) and specificity of 91% (88%-93%) for MRI [12]. FDG-PET/MRI Skull Base to Mid-Thigh Although still not in widespread clinical use, research has shown PET/MRI to be a promising new modality for comprehensive examination of cervical cancer disease extent. The MRI examination offers ideal imaging of the primary tumor for local extent evaluation, whereas the PET component offers superior sensitivity for the detection of nodal and hematogenous metastases. This is supported by a prospective study of 53 patients with cervical cancer that showed whole body PET/MRI performed comparably to MRI alone for local disease assessment with 85% accuracy versus 87% but better for the detection of lymph node metastases demonstrating 83% sensitivity, 90% specificity, and 87% accuracy compared to 71%, 83%, and 77%, respectively for MRI alone [14].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Considering local invasion, a study of 33 patients who underwent pretreatment PET/MRI showed a higher area under the curve than MRI alone for the detection of parametrial invasion (0.89 versus 0.73), vaginal invasion (85% versus 74%), and deep cervical stromal invasion (96% versus 74%) [15]. In addition to the staging evaluation, PET/MRI offers prognostic information with a higher maximum standardized uptake value (SUVmax) associated with poorer prognosis [16,17] and was found to be an independent predictor of progression-free survival (hazard radio [HR] = 4.57). MRI Pelvis Without and With IV Contrast MRI is used to determine invasive cervical cancer tumor size and the extent of local invasion. Its superior soft tissue characterization allows for a more accurate staging assessment than can be obtained by CT or ultrasound (US) [11,18-20]. T2-weighted noncontrast sequences in the sagittal plane, axial oblique plane through the axis of the cervix, and coronal oblique planes though the axis of the cervix are the foundations of the anatomic assessment [21,22]. One prospective study of 100 patients with prehysterectomy MRIs showed 86% agreement between MRI and surgical pathologic findings for tumor size and local extent evaluation (95% CI, 76.3%-90.9%) [23]. Another meta- MRI Pelvis Without IV Contrast Although IV contrast administration is preferred, MRI pelvis without IV contrast may improve the conspicuity of small lesions compared with other imaging modalities [27,28] and may help to distinguish between cervical and endometrial primaries when the tumor involves both anatomic regions [29]. The T2-weighted noncontrast sequences in the sagittal plane, axial oblique plane through the axis of the cervix, and coronal oblique planes though the axis of the cervix are the foundations of the anatomic assessment [21,22], and the DWI/ADC images may help to detect small lesions.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Because of its inherent superior soft tissue contrast, a noncontrast MRI is strongly preferred to a noncontrast CT. US Pelvis Transabdominal Transabdominal US of the pelvis plays a limited role in local staging of cervical cancers because of poorer evaluation of the gynecologic organs. For pelvic imaging, transvaginal US (TVUS) is preferred. US Pelvis Transvaginal TVUS of the pelvis has been evaluated as an alternative to MRI for the assessment of local disease extent. One meta-analysis, which compared the performance of US and MRI for local extent of disease assessment, showed similar performance between the 2 modalities, with US demonstrating a pooled sensitivity of 78% (95% CI, 48%- 93%) and specificity of 96% (95% CI, 84%-99%) for parametrial involvement, compared to 68% sensitivity (95% CI, 54%-80%) and 91% specificity (95% CI, 94%-95%) for MRI [30]. Contrast-enhanced US also shows similar diagnostic performance to MRI, with a study of 108 women with invasive cervical cancer who underwent both contrast-enhanced US and MRI demonstrating strong correlation between the 2 modalities for tumor size (r = 0.84- 0.88) and moderate concordance for vaginal and parametrial invasion [31]. Weaknesses of TVUS compared to MRI include the assessment of bulky tumors >4 cm [32]. Variant 2: Initial systemic staging of pretreatment cervical cancer; assessment of lymph node and distant metastases (N/M staging). As of 2018, the FIGO staging system incorporates radiologic and pathologic data in the assessment [2]. A new stage was created as a result of this, corresponding to radiologically suspected or pathologically confirmed nodal disease in the pelvis (IIIC1) and para-aortic (IIIC2) stations. When unsuspected nodal disease is found at surgical pathology, adjuvant radiation is necessary, with high morbidity. Therefore, the identification of nodal disease on preoperative imaging is paramount for the selection of the appropriate treatment strategy.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. CT Abdomen and Pelvis With IV Contrast CT abdomen and pelvis with IV contrast may be used for the assessment of nodal and distant metastatic disease. Reported rates of unsuspected metastatic disease at a diagnosis range from 6.2% in a study of 1,158 consecutively evaluated cervical cancer patients to 13.7% in a study of patients with stage IB2 or greater disease on local Follow-up of Invasive Cancer of the Cervix assessment. The other most common sites of metastatic disease are in the lung, peritoneum, supraclavicular lymph nodes, liver, and bone [33-35]. With regards to nodal disease assessment, a meta-analysis of 115 studies published from 2000 to 2019 showed contrast-enhanced CT demonstrated good, although slightly inferior performance, compared to MRI and PET, with a pooled sensitivity and specificity of 51% (95% CI, 36%-67%) and 87% (95% CI, 81%-92%), compared to 57% (95% CI, 49%-64%) and 93% (95% CI, 89%-95%) for MRI, and 57% (95% CI, 48%-65%) and 95% (95% CI, 93%-97%) for PET [12]. Another meta-analysis of 72 studies found similar results with CT demonstrating a pooled sensitivity of 58% and a specificity of 92%, compared to 56% and 93% for MRI and 75% and 98% for PET [36]. These differences in performance are likely accounted for by difficulty in detecting disease in nodes <1 cm in size, for which MRI or PET are more sensitive. CT Abdomen and Pelvis Without and With IV Contrast The addition of noncontrast CT abdomen and pelvis images would not appreciably add to the contrast-enhanced CT evaluation. CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast provides very poor soft tissue characterization in the pelvis [13] and therefore is not useful for the evaluation of invasive cervical cancer.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Nodal metastases may be detected on a noncontrast-enhanced examination based on an abnormal size of >0.8 cm in axial short axis in the pelvis or >1 cm in axial short axis in the abdomen, an abnormally rounded shape, or loss of the normal fatty hilum. However, sensitivity may be decreased because of the difficulties distinguishing lymph nodes from adjacent vessels and/or small bowel loops. CT Chest With IV Contrast Evaluation of the chest for metastatic disease is critical for patients with stage IB2 or greater disease because the rate of occult metastases is as high as 38% in this population [33]. Given its superior diagnostic performance for the detection of small pulmonary nodules, chest CT is preferred to chest radiography for this purpose. Although IV contrast is not necessary for the evaluation of the lung parenchyma and pleural spaces, it is strongly preferred for the detection of abdominopelvic metastases. Therefore, CT chest with IV contrast is commonly performed along with the abdomen and pelvis examination. CT Chest Without and With IV Contrast The addition of noncontrast CT chest images would not appreciably add to the contrast-enhanced CT evaluation. CT Chest Without IV Contrast Evaluation of the chest for metastatic disease is critical for patients with stage IB2 or greater disease because the rate of occult metastases is as high as 38% in this population [33]. Given its superior diagnostic performance for the detection of small pulmonary nodules, chest CT is preferred to chest radiography for this purpose. FDG-PET/CT Skull Base to Mid-Thigh PET/CT is the current modality of choice for assessment for nodal and distant metastatic disease. The National Comprehensive Cancer Network (NCCN) guidelines recommend a PET/CT be performed at the time of initial staging for all patients with stage IB2 disease or greater, given a rate of unsuspected distant metastatic disease of 13.7% in this population [33,37].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. A multicenter study of 153 cervical cancer patients showed PET/CT had an overall sensitivity, specificity, PPV, and NPV of 54.8%, 97.7%, 79.3%, and 93.1%, respectively, for the detection of distant cervical cancer metastases. The most common sites of distant metastatic disease are the lung, peritoneum, supraclavicular lymph nodes, liver, and bone [33-35]. With regards to lymph node assessment, a meta-analysis of 72 studies showed PET to have superior performance to MRI and CT, with a pooled sensitivity of 75% and a specificity of 98%, compared to 56% and 93% for MRI and 58% and 92% for CT [36]. Another meta-analysis of 115 studies published from 2000 to 2019 also showed PET had superior performance, with a pooled sensitivity and specificity of 57% (95% CI, 48%-65%) and 95% (95% CI, 93%-97%) compared to 57% (95% CI, 49%-64%) and 93% (95% CI,89%-95%) for MRI and 51% (95% CI, 36%- 67%) and 87% (95% CI, 81%-92%) for CT [12]. The high specificity of PET/CT for nodal assessment allows for a high NPV of 93.1% [38]. This prospective study in 153 patients also showed that the addition of PET to diagnostic CT was associated with a mild but statistically significant increase in sensitivity to detect abdominal nodal metastases in advanced cervical cancer [38]. Follow-up of Invasive Cancer of the Cervix FDG-PET/MRI Skull Base to Mid-Thigh Although still not in widespread clinical use, research has shown PET/MRI to be a promising new modality for comprehensive examination of cervical cancer disease extent. The MRI examination offers ideal imaging of the primary tumor for local extent evaluation, whereas the PET component offers superior sensitivity for the detection of nodal and hematogenous metastases.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. This is supported by a prospective study of 53 patients with cervical cancer that showed whole body PET/MRI performed comparably to MRI alone of the local disease extent with 85% accuracy versus 87% but was better for the detection of lymph node metastases demonstrating 83% sensitivity, 90% specificity, and 87% accuracy compared to 71%, 83%, and 77%, respectively, for MRI alone [14]. Higher SUVmax is associated with poorer prognosis [16,17]. In addition to the staging evaluation, PET/MRI offers prognostic information with a higher SUVmax associated with poorer prognosis [16,17], and in 1 study was found to be an independent predictor of progression-free survival (HR = 4.57). MRI Abdomen Without and With IV Contrast MRI abdomen without and with IV contrast may be used for the assessment of nodal and distant metastatic disease, preferably with IV contrast. It may be obtained along with the pelvic MRI performed for local disease extent assessment. If these examinations are obtained simultaneously, dynamic contrast-enhanced (DCE) imaging should be obtained of the pelvis to prioritize the local extent of disease assessment, with only delayed contrast-enhanced imaging obtained of the abdomen. With regards to nodal disease assessment, nodes are considered abnormal on MRI if their axial short axis is >1 cm in the abdomen or if they display abnormal morphologic characteristics such as rounded shape, loss of the normal fatty hilum, heterogenous signal, or more pronounced diffusion restriction than uninvolved lymph nodes. Using these criteria, a meta-analysis of 115 studies published from 2000 to 2019 showed MRI performed comparably to PET for nodal metastatic disease assessment, with a pooled sensitivity and specificity of 57% (95% CI, 49%-64%) and 93% (95% CI, 89%-95%), compared to 57% (95% CI, 48%-65%) and 95% (95% CI, 93%-97%) for PET.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. In this study, MRI performed better than CT, which had a pooled sensitivity and specificity of 51% (95% CI, 36%- 67%) and 87% (95% CI, 81%-92%), respectively [12]. Another meta-analysis of 72 studies showed MRI had comparable performance to CT and inferior performance to PET, with a sensitivity of 58% and a specificity of 93% compared to 75% and 98% for PET and 58% and 92% for CT [36]. MRI Abdomen Without IV Contrast MRI abdomen without IV contrast may be employed for the assessment of nodal and distant metastatic disease and may be obtained along with the pelvic MRI performed for local disease extent assessment. Although IV contrast administration is preferred because it may increase the conspicuity of small lesions, it still demonstrates inherent superior soft tissue contrast compared to CT, and the DWI/ADC images may help to detect small metastatic foci. MRI Pelvis Without and With IV Contrast Evaluation for pelvic and lower para-aortic lymph node metastases can be performed at the time of local disease assessment, preferably with IV contrast. Nodes are considered abnormal on MRI if their axial short axis is >0.8 cm in the pelvis or if they display abnormal morphologic characteristics such as rounded shape, loss of the normal fatty hilum, heterogenous signal, or more pronounced diffusion restriction than uninvolved lymph nodes. Using these criteria, a meta-analysis of 115 studies published from 2000 to 2019 showed MRI performed comparably with PET with a pooled sensitivity and specificity of 57% (95% CI, 49%-64%) and 93% (95% CI, 89%-95%), compared to 57% (95% CI, 48%-65%) and 95% (95% CI, 93%-97%) for PET. In this study, MRI performed better than CT, which had a pooled sensitivity and specificity of 51% 57% (95% CI, 49%-64%) and 93% (95% CI, 89%-95%), compared to 57% (95% CI, 48%-65%) and 95% (95% CI, 93%-97%), respectively [12].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Another meta-analysis of 72 studies showed MRI had a comparable performance to CT and an inferior performance to PET, with a sensitivity of 58% and a specificity of 93% compared to 75% and 98% for PET and 58% and 92% for CT [36]. MRI Pelvis Without IV Contrast Evaluation for pelvic and lower para-aortic lymph node metastases can be performed at the time of local disease assessment. Nodes are considered abnormal on MRI if their axial short axis is >1 cm or if they display abnormal morphologic characteristics such as rounded shape, loss of the normal fatty hilum, heterogenous signal, or more pronounced diffusion restriction than uninvolved lymph nodes. Although IV contrast administration is preferred because it may increase the conspicuity of small lesions, it still demonstrates inherent superior soft tissue contrast compared to nonenhanced CT, and MRI may help detect even subcentimeter-sized disease foci [39]. In a study of 53 patients, MRI was able to detect tumors as small as 0.6 cm but missed a 0.3 cm sized lesion [40]. Follow-up of Invasive Cancer of the Cervix Radiography Chest Chest radiographs are recommended by the Society of Gynecologic Oncology for the detection of pulmonary metastases (in the form of pulmonary nodules or pleural effusions). However, chest radiographs have a low rate of detection of thoracic metastases (ranging from 0%-20%) compared to 80% to 95% reported by chest CT [41,42]. Therefore, chest CT is preferred. US Abdomen Abdominal US can be used to detect hydronephrosis, which may indicate parametrial invasion and ureteral obstruction corresponding to stage IIIb disease. Although abdominal US may also show metastatic disease in other organs such as the liver or upper abdominal lymph nodes, its narrow field of view makes it a poor modality for a complete nodal and metastatic disease assessment. Cross-sectional imaging with CT or MRI is preferred for this evaluation.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. US Pelvis Transabdominal Transabdominal US of the pelvis plays a limited role in the staging of cervical cancers because of its incomplete evaluation of the gynecologic organs. For pelvic imaging, TVUS is preferred. US Pelvis Transvaginal Although TVUS of the pelvis plays an important role in local disease assessment, its limited depth of penetration makes it a poor choice of modality for a complete nodal and metastatic disease assessment. Cross-sectional imaging is preferred. Variant 3: Initial treatment response assessment of cervical cancer after chemoradiation. This variant primarily applies to response assessment of the locally advanced primary tumor after chemoradiation. Literature on assessment of initial treatment response of cervical cancer after chemoradiation is evolving, with emphasis on the use of MRI or PET/CT, which can help in both response assessment and detection of complete response versus residual disease. This information is critical for the management because patients with refractory disease (presence of residual tumor after 6 months of completion of treatment) in the pelvis without distant metastases may be considered for pelvic exenteration. There is also a growing body of literature exploring the use of the functional parameters such as DWI or ADC images on MRI or metabolic parameters on PET/CT as prognostic biomarkers. CT Abdomen and Pelvis With IV Contrast There is no relevant literature supporting the use of CT abdomen and pelvis with IV contrast for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation. CT may be used for response assessment of nodal and distant metastatic disease [37]. Use of IV contrast material is generally preferred. If there is distant metastatic disease, imaging of the chest, abdomen, and pelvis is concurrently performed.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature supporting the use of CT abdomen and pelvis without and with IV contrast for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation. CT may be used for response assessment of nodal and distant metastatic disease [37]; however, a dual-phase study without and with IV contrast is unnecessary. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature supporting the use of CT abdomen and pelvis without IV contrast for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation. CT may be used for response assessment of nodal and distant metastatic disease [37]. Although the use of IV contrast material is preferred, the assessment may be performed without IV contrast. If there is distant metastatic disease, imaging of the chest, abdomen, and pelvis is concurrently performed. CT Chest With IV Contrast CT chest with IV contrast is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation; however, it may be used for response assessment of distant metastatic disease [37]. Use of IV contrast material is generally preferred. If there is distant metastatic disease, imaging of the chest, abdomen, and pelvis is concurrently performed. Follow-up of Invasive Cancer of the Cervix CT Chest Without and With IV Contrast CT chest without and with IV contrast is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation; however, it may be used for response assessment of distant metastatic disease [37]. Dual-phase study without and with IV contrast is unnecessary.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. CT Chest Without IV Contrast CT chest without IV contrast is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation; however, it may be used for response assessment of distant metastatic disease [37]. Although the use of IV contrast material is preferred, the assessment may be performed without IV contrast. If there is distant metastatic disease, imaging of the chest, abdomen, and pelvis is concurrently performed. FDG-PET/CT Skull Base to Mid-Thigh Multiple studies have shown that FDG-PET/CT is useful in assessing metabolic response of cervical cancer to chemoradiation [43-47]. In a prospective study with 88 patients, changes in FDG-PET/CT metabolic parameters such as SUVmax and total lesion glycolysis (TLG) helped predict histopathological response to chemoradiation [48]. In a retrospective study involving 82 patients, metabolic tumor volume (MTV), TLG, and nodal involvement on PET/CT were the significant predictors of response [45]. Higher tumor SUVmax and TLG are also shown to be significantly associated with poor response to chemoradiation [49], whereas MTV has been shown to adversely affect prognosis [50]. A meta-analysis including 12 studies with 1,104 patients demonstrated that response on FDG- PET/CT was a significant prognostic factor and suggested that PET/CT has a role in follow-up assessment of patients with cervical cancer [51]. PET/CT reportedly has better performance than MRI for the detection of active disease after chemoradiation. In a study that included 55 patients, sensitivity, specificity, and accuracy of PET/CT for detection of residual disease was 60%, 100%, and 89%, whereas that of MRI was 27%, 100%, and 80%, respectively [52]. FDG-PET/MRI Skull Base to Mid-Thigh The literature on the use of FDG-PET/MRI for response assessment of cervical cancer is limited. FDG-PET/MRI likely has a role in assessment of response after chemoradiation.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. In a prospective case control study with 45 patients, SUVmax was an independent predictor of progression-free survival [53]. In addition, MTV and minimum ADC helped predict progression-free survival in stage I and II disease. Although both FDG-PET and MRI are shown to have utility in response assessment of patients with cervical cancer, additional research is needed to assess the utility of FDG-PET/MRI in these patients. MRI Abdomen Without and With IV Contrast MRI abdomen without and with IV contrast is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation; however, it may be used for response assessment of distant metastatic disease [37]. If there is distant metastatic disease, imaging of the chest, abdomen, and pelvis is concurrently performed. MRI Abdomen Without IV Contrast MRI abdomen without IV contrast is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation; however, it may be used for response assessment of distant metastatic disease [37]. If there is distant metastatic disease, imaging of the chest, abdomen, and pelvis is concurrently performed. MRI Pelvis Without and With IV Contrast MRI pelvis without and with IV contrast has a role in assessment of response of cervical cancer after chemoradiation. Given its excellent soft tissue contrast, MRI allows excellent visualization of tumor and allows serial volume measurements as well as early assessment of therapy failure by demonstrating increase in size [54]. Response to treatment results in fibrotic change, and reconstitution of normal low T2 signal of the cervical stroma is the most reliable indicator of complete response to radiation therapy [54,55]. Residual or refractory disease has intermediate T2 signal and restricted diffusion. MRI also has a likely role in patients with early-stage cervical cancer following conization.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. A retrospective study of 55 patients found that MRI had overall 73% accuracy in detection of pathologically proved residual tumor [56]. In a small retrospective study of 32 patients, T2-weighted images were useful in assessing change in the tumor volume [57]. In a study of 185 patients, MRI was able to demonstrate the change in size of primary tumor after radiation. Initial tumor size and the rate of decrease of tumor size were significantly associated with local recurrence-free survival and overall survival rates [58]. A meta-analysis including 4 studies and 147 patients Follow-up of Invasive Cancer of the Cervix demonstrated that MRI had 83.5% sensitivity, 88.5% specificity, and 84.3% accuracy for detection of residual tumor after brachytherapy [59]. In other studies, the sensitivity, specificity, and accuracy of MRI was 27% to 69%, 71% to 100%, and 71% to 80%, with 1 of these studies concluding that MRI had an overall lower performance than PET/CT [52,60]. In another study, there was a relatively low agreement between posttreatment MRI and pathology for assessment of tumor size [23]. A small retrospective study of 51 patients also demonstrated that MRI had high sensitivity and low specificity in identifying persistent parametrial invasion after neoadjuvant chemotherapy [14]. DWI and DCE MRI likely have a role in assessment of these patients. In a retrospective study of 52 patients using DWI and DCE MRI, an initial increase in tumor signal intensity on DCE MRI, higher than myometrium, as well as low signal on ADC images were significantly associated with incomplete response [61]. In this study, there was excellent agreement between the 3 readers. In a meta-analysis, pretreatment ADC values alone were not reliable in assessing treatment response [62]; however, other studies have indicated that multiparametric MRI with DWI and DCE images together may help predict response to chemoradiation [63,64].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Patients with disease recurrence also had a lower ADC both pre- and posttreatment, as well as had a smaller interval change in ADC values [65]. In a retrospective study with 102 patients, tumors with infiltrative growth pattern on MRI were associated with a lower overall and locoregional recurrence-free survival rates after chemoradiation [66]. Finally, MRI is also helpful for assessment of posttreatment complications [54]. MRI Pelvis Without IV Contrast MRI pelvis without IV contrast may have a role in assessment of response of cervical cancer after chemoradiation; however, use of IV contrast may add value. In a study of 185 patients, MRI was able to demonstrate the change in the size of the primary tumor after radiation, and initial tumor size and the rate of decrease of tumor size were significantly associated with local recurrence-free and overall survival rates [58]. A meta-analysis including 4 studies and 147 patients, MRI had 83.5% sensitivity, 88.5% specificity, and 84.3% accuracy for detection of residual tumor after brachytherapy; however, it remains unclear if these results also translate to MRI without IV contrast [59]. MRI parameters on DWI and DCE images also likely have a role in assessment of these patients. In a meta- analysis, pretreatment ADC values on MRI alone were not reliable in assessing treatment response [62]; however, other studies have indicated that multiparametric MRI with DWI and DCE images together may help predict response to chemoradiation [63,64]. In another small retrospective study in 32 patients, T2-weighted images were shown to be useful in assessing changes in the tumor volume [57]. In a retrospective study with 102 patients, tumors with infiltrative growth pattern on MRI were associated with a lower overall and locoregional recurrence-free survival rates after chemoradiation [66].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Radiography Chest Chest radiography is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation; however, it may be used for detection of distant metastatic disease [37]. US Abdomen Abdominal US is not useful for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation. US Pelvis Transabdominal There is no relevant literature to support the use of transabdominal pelvic US for the evaluation of initial treatment response assessment of primary cervical cancer after chemoradiation. US Pelvis Transvaginal In a prospective study of 128 women, TVUS showed an overall 92% accuracy in predicting response to chemotherapy, with decreased tumor volume being the most important association of response [67]. In another retrospective study of 51 patients, TVUS had a high sensitivity and specificity in identifying persistent parametrial invasion after neoadjuvant chemotherapy [68]. Another prospective study with 88 patients showed that after 2 weeks of neoadjuvant treatment, TVUS was able to demonstrate higher tumor volume in patients with partial response compared to those with complete response [69]. In the same study, additional color Doppler and contrast features was also significantly different in the partial- and complete-response groups, both before and after 2 weeks of treatment; however, the sensitivity (48%-77%) and specificity (58%-84%) of various US parameters were not high enough for accurate prospective prediction of treatment response [69]. Follow-up of Invasive Cancer of the Cervix Variant 4: Surveillance of treated cervical cancer in asymptomatic patients. Recurrent cervical cancer is defined as local regrowth of tumor, presence of distant metastases, or a combination of both 6 months after the completion of treatment.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. The recurrence rates are in the range of 10% to 20%, and the majority of recurrences occur within 2 to 3 years after the initial treatment [5]. Cervix, parametrium, vaginal vault, pelvic sidewall, or retroperitoneal lymph nodes are the most common sites of recurrence. Patients with recurrent disease are often symptomatic. As a result, the Society of Gynecologic Oncology recommends against routine imaging surveillance of posttreatment cervical cancer patients [5]. CT Abdomen and Pelvis With IV Contrast For stage I patients who undergo nonfertility sparing treatment, use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and degree of clinical concern such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage II to IV patients, CT of the abdomen and pelvis may be used within 3 to 6 months after completion of therapy; however, NCCN guidelines indicate a preference for PET/CT for this purpose [37]. Use of IV contrast is generally preferred. Imaging of the chest, abdomen, and pelvis is often concurrently performed. CT Abdomen and Pelvis Without and With IV Contrast For stage I patients who undergo nonfertility sparing treatment, use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage II to IV patients, CT of the abdomen and pelvis may be used within 3 to 6 months after completion of therapy; however, NCCN guidelines indicate a preference for PET/CT for this purpose [37]. Dual-phase study without and with IV contrast is unnecessary.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. CT Abdomen and Pelvis Without IV Contrast For stage I patients who undergo nonfertility sparing treatment, use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage II to IV patients, CT of the abdomen and pelvis may be used within 3 to 6 months after completion of therapy; however, NCCN guidelines indicate a preference for PET/CT for this purpose [37]. Although the use of IV contrast material is preferred, the assessment may be performed without IV contrast. Imaging of the chest, abdomen, and pelvis is often concurrently performed. CT Chest With IV Contrast For stage I patients who undergo nonfertility sparing treatment, the use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage II to IV patients, CT of the chest may be used within 3 to 6 months after completion of therapy; however, NCCN guidelines indicate a preference for PET/CT for this purpose [37]. Use of IV contrast is generally preferred. Imaging of the chest, abdomen, and pelvis is often concurrently performed. CT Chest Without and With IV Contrast For stage I patients who undergo nonfertility sparing treatment, the use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage II to IV patients, CT of the chest may be used within 3 to 6 months after completion of therapy; however, NCCN guidelines indicate a preference for PET/CT for this purpose [37]. Dual-phase study without and with IV contrast is unnecessary.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. CT Chest Without IV Contrast For stage I patients who undergo nonfertility sparing treatment, the use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage II to IV patients, CT of the chest may be used within 3 to 6 months after completion of therapy; however, NCCN guidelines indicate preference for PET/CT for this purpose [37]. Although the use of IV contrast material is preferred, the assessment may be performed without IV contrast. Imaging of the chest, abdomen, and pelvis is often concurrently performed. Follow-up of Invasive Cancer of the Cervix FDG-PET/CT Skull Base to Mid-Thigh FDG PET/CT is useful in the evaluation of local and distant recurrence even in asymptomatic patients, as well as in excluding metastatic disease in patients with pelvic recurrence amenable to radical surgery [5,37,54]. A meta- analysis including 18 studies and 762 patients showed that PET/CT had a pooled sensitivity and specificity of 92% (95% CI, 91%-94%) and 84% (95% CI, 74%-91%) and an area under the curve of 0.95 [70]. In another meta- analysis, the pooled sensitivity and specificity of PET/CT to detect local recurrence was 82% (95% CI, 72%-90%) and 98% (95% CI, 96%-99%), whereas that for distant metastasis was 87% (95% CI, 80%-92%) and 97% (95% CI, 96%-98%) [71]. In a retrospective study with 84 patients, higher MTV was associated with a higher rate of recurrence in patients with stage IIB to IVA cervical cancer [72]. Additional studies have indicated that metabolic parameters including SUVmax, MTV, and TLG may help predict outcomes including overall survival and therefore can influence the follow-up imaging strategy [43,46,73,74].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Per NCCN guidelines, for stage I patients who undergo nonfertility sparing treatment, the use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern, such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. Stage IB3 patients of those with risk factors such as positive nodes, parametrial extension. or positive margins may undergo PET/CT at 3 to 6 months after completion of treatment [37]. Generally, NCCN guidelines recommend the use of PET/CT over CT for the evaluation of metastatic disease [37]. FDG-PET/MRI Skull Base to Mid-Thigh In a prospective study of 45 patients with newly diagnosed cervical cancer, an SUVmax was an independent predictor of progression-free survival (HR = 4.57, P < . 05). Minimum ADC was an independent predictor of overall survival [53]. Additional studies have indicated that metabolic parameters including SUVmax, MTV, and TLG may help predict outcomes including overall survival [49,73,74]. A retrospective study on 31 patients found PET/MRI to be useful in assessment of recurrent and metastatic disease and also found that that was a significant inverse correlation between SUVmax and ADC values [75]. Another small prospective study showed that PET/MRI was able to detect both local and distant recurrence of cervical cancer and found a similar significant inverse correlation between SUVmax and ADC values [76]. MRI Abdomen Without and With IV Contrast At present there is no relevant literature to support the use of MRI abdomen without and with IV contrast for surveillance of patients with asymptomatic cervical cancer [37]. For stage II to IV patients, NCCN guidelines recommend PET/CT (preferred) or CT of the chest, abdomen, and pelvis [37]. Imaging of the chest, abdomen, and pelvis is often concurrently performed.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. MRI Abdomen Without IV Contrast At present there is no relevant literature to support the use of MRI abdomen without IV contrast for surveillance of patients with asymptomatic cervical cancer [37]. For stage II through IV patients, NCCN guidelines recommend PET/CT (preferred) or CT of chest, abdomen and pelvis [37]. If MRI is performed, IV contrast should be used unless contraindicated. Imaging of the chest, abdomen, and pelvis is often concurrently performed. MRI Pelvis Without and With IV Contrast MRI pelvis has a role in the surveillance imaging after initial treatment; however, at present there is no consensus on the time interval of follow-up imaging after the initial treatment or the optimal frequency of follow-up imaging [54]. Treatment-related changes in T2 signal can limit early detection of recurrent tumor, which is seen as heterogeneous intermediate to high T2 signal, diffusion-restricting tissue on the background of established low- signal radiation-induced fibrosis [54]. In a meta-analysis including 4 studies and 147 patients, MRI had 83.5% sensitivity, 88.5% specificity, and 84.3% accuracy for detection of residual tumor after brachytherapy [59]. In another retrospective study, MRI had an 81.8% PPV and an 87.5% NPV in detecting histologically confirmed recurrent disease in patients who did not have complete response on posttreatment PET/CT [44]. MRI parameters are also shown to predict recurrence-free interval and therefore may influence the imaging surveillance strategy. In a retrospective study of 103 patients with stage IB to IVA cervical cancer, the smaller increase in ADC values and the smaller decrease in tumor volume during chemoradiation or radiation treatment were predictors of tumor recurrence over a median follow-up period of 2.7 years [77].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. In a retrospective study with 102 patients, tumors with infiltrative growth pattern on MRI were associated with a lower overall and locoregional recurrence-free survival rates after chemoradiation [66]. Additional studies and a meta-analysis have also indicated that MRI features, including ADC value and tumor volume, of primary cervical cancer as well as nodal disease can help predict Follow-up of Invasive Cancer of the Cervix metastasis-free and overall survival rates [77-81]. These findings may influence the surveillance strategy of patients with cervical cancer. Per NCCN guidelines, for stage I patients who undergo nonfertility sparing treatment, the use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and degree of clinical concern, such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage I patients who undergo fertility sparing treatment, MRI with IV contrast may be performed at 3 to 6 months and then yearly for 2 to 3 years [37]. For stage II through IV patients, pelvic MRI with IV contrast should be considered 3 to 6 months after completion of therapy [37]. MRI Pelvis Without IV Contrast MRI pelvis with IV contrast is the preferred study, but without IV contrast may also be useful. In a retrospective study of 103 patients with stage IB-IVA cervical cancer, the smaller increase in ADC values and the smaller decrease in tumor volume during chemoradiation or radiation treatment were predictors of tumor recurrence over a median follow-up period of 2.7 years [77]. Additional studies have also indicated that MRI features, including ADC value and tumor volume, of primary cervical cancer as well as nodal disease can help predict metastasis-free and overall survival rates [77-80]. These findings may influence the surveillance strategy of patients with cervical cancer.


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Per NCCN guidelines, for stage I patients who undergo nonfertility sparing treatment, the use of imaging for surveillance of cervical cancer in asymptomatic patients should be based on symptomatology and the degree of clinical concern, such as clinical examination findings or pelvic, abdominal, or pulmonary symptoms [37]. For stage I patients who undergo fertility sparing treatment, MRI may be performed at 3 to 6 months and then yearly for 2 to 3 years [37]. For stage II through IV patients, pelvic MRI should be considered at 3 to 6 months after completion of therapy [37]. IV contrast should be used unless contraindicated [37]. Radiography Chest There is no relevant literature to support the use of chest radiography in the surveillance of patients with cervical cancer [5,37]. US Abdomen There is no relevant literature to support the use of US abdomen in the surveillance of patients with cervical cancer [5,37]. US Pelvis Transabdominal There is no relevant literature to support the use of pelvic transabdominal US in the surveillance of patients with cervical cancer [5,37]. US Pelvis Transvaginal There is no relevant literature to support the use of pelvic TVUS in the surveillance of patients with cervical cancer [5,37]. Variant 5: Evaluation of known or suspected cervical cancer local recurrence or distant metastatic disease. Follow-up imaging. The majority of patients with recurrent cervical cancer are symptomatic, with the symptoms ranging from abdominal and pelvic pain, leg symptoms such as pain or lymphedema, vaginal bleeding or discharge, urinary symptoms, cough, and weight loss [5]. CT, MRI, and PET/CT all have a role in detection of local or distant recurrence in symptomatic patients, as well as in the response assessment after chemotherapy. CT Abdomen and Pelvis With IV Contrast CT may be used for the assessment of known distant recurrence, preferably with use of IV contrast [37].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. In a meta- analysis that included 4 studies that evaluated use of CT for this purpose, the summary estimate of the sensitivity of CT was 90% (95% CI, 82%-94%), and the specificity was 76% (95% CI, 44%-93%) [82]. Imaging of the chest, abdomen, and pelvis is often concurrently performed for evaluation of distant metastatic disease. CT Abdomen and Pelvis Without and With IV Contrast CT may be used for assessment of known distant recurrence, preferably with use of IV contrast [37]. In a meta- analysis that included 4 studies that evaluated use of CT for this purpose, the summary estimate of the sensitivity of CT was 90% (95% CI, 82%-94%), and the specificity was 76% (95% CI, 44%-93%) [82]. Dual-phase study without and with IV contrast is unnecessary. Follow-up of Invasive Cancer of the Cervix CT Abdomen and Pelvis Without IV Contrast CT may be used for the assessment of known distant recurrence, preferably with the use of IV contrast [37]. In a meta-analysis that included 4 studies that evaluated the use of CT for this purpose, the summary estimate of the sensitivity of CT was 90% (95% CI, 82%-94%), and the specificity was 76% (95% CI, 44%-93%) [82]. Imaging of the chest, abdomen, and pelvis is often concurrently performed for evaluation of distant metastatic disease. CT Chest With IV Contrast CT may be used for the assessment of known distant recurrence, preferably with the use of IV contrast [37]. In a meta-analysis that included 4 studies that evaluated the use of CT for this purpose, the summary estimate of the sensitivity of CT was 90% (95% CI, 82%-94%), and the specificity was 76% (95% CI, 44%-93%) [82]. Imaging of the chest, abdomen, and pelvis is often concurrently performed for evaluation of distant metastatic disease. CT Chest Without and With IV Contrast CT may be used for the assessment of known distant recurrence, preferably with the use of IV contrast [37].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. In a meta-analysis that included 4 studies that evaluated use of CT for this purpose, the summary estimate of the sensitivity of CT was 90% (95% CI, 82%-94%), and the specificity was 76% (95% CI, 44%-93%) [82]. Dual-phase study without and with IV contrast is unnecessary. CT Chest Without IV Contrast CT may be used for the assessment of known distant recurrence, preferably with the use of IV contrast [37]. In a meta-analysis that included 4 studies that evaluated use of CT for this purpose, the summary estimate of the sensitivity of CT was 90% (95% CI, 82%-94%), and the specificity was 76% (95% CI, 44%-93%) [82]. Imaging of the chest, abdomen, and pelvis is often concurrently performed for evaluation of distant metastatic disease. FDG-PET/CT Skull Base to Mid-Thigh NCCN guidelines support the use of PET/CT over CT for the evaluation of metastatic disease [37]. In patients with suspected recurrence, FDG-PET/CT is useful in detection of local and distant disease, as well as in excluding metastatic disease in patients with pelvic recurrence who are amenable to radical surgery [37,54]. A meta-analysis of 9 PET/CT studies in mostly symptomatic women found an overall sensitivity of 95% (95% CI, 91%-97%) and a specificity of 87% (95% CI, 82%-91%) for detection of recurrent disease [82]. PET/CT is also helpful in assessment of metabolic response and has been shown to correlate well with radiologic response [47]. FDG-PET/MRI Skull Base to Mid-Thigh There is limited literature on use of PET/MRI for the evaluation of known or suspected recurrent disease; however, a retrospective study on 31 patients found PET/MRI to be useful in the assessment of recurrent and metastatic disease and also found that there was a significant inverse correlation between SUVmax and ADC values [75].


Pretreatment Evaluation and Follow up of Invasive Cancer of the Cervix. Another small prospective study showed that PET/MRI was able to detect both local and distant recurrence of cervical cancer and found a similar significant inverse correlation between SUVmax and ADC values [76]. These studies indicate a potential of PET/MRI for concurrent assessment of both PET- and MRI-based functional biomarkers. MRI Abdomen Without and With IV Contrast MRI may be useful for the assessment of distant disease and for the assessment of response, preferably with the use of IV contrast [37]. Imaging of the chest, abdomen, and pelvis is often concurrently performed for evaluation of distant metastatic disease. MRI Abdomen Without IV Contrast MRI may be used for the assessment of distant disease and for the assessment of response, preferably with the use of IV contrast [37]. Imaging of the chest, abdomen, and pelvis is often concurrently performed for evaluation of distant metastatic disease. MRI Pelvis Without and With IV contrast Per NCCN guidelines, pelvic MRI is useful for patients with suspected recurrence, preferably with IV contrast [37]. MRI Pelvis Without IV contrast Per NCCN guidelines, pelvic MRI is useful for patients with suspected recurrence, preferably with IV contrast [37]. Radiography Chest There is no relevant literature to support the use of chest radiography in the surveillance of patients with cervical cancer [5,37]. The rate of detection of thoracic disease on chest radiograph is reportedly 20% to 47% [5]. Follow-up of Invasive Cancer of the Cervix US Abdomen There is no relevant literature to support the use of US abdomen in the surveillance of patients with cervical cancer [5,37]. US Pelvis Transabdominal There is no relevant literature to support the use of pelvic transabdominal US in the surveillance of patients with cervical cancer [5,37]. Follow-up of Invasive Cancer of the Cervix Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs.  Diagnosis of PE is challenging because of the nonspecific nature of the clinical presentation, with associated symptoms such as chest pain, shortness of breath, and tachycardia that may mimic other pulmonary or cardiac conditions. The diagnostic challenge of PE is most commonly addressed with clinical scoring algorithms such as the Wells criteria and the Geneva score [6-8], D-dimer testing, and specialized CT angiography (CTA) [9], during which the images are acquired with a timing of the iodinated contrast bolus to best opacify the pulmonary arteries. In hemodynamically stable patients with a low or intermediate clinical likelihood of PE, normal results on D-dimer testing obviates the need for PE imaging. When patients do not fall into these categories, CT pulmonary angiography (CTPA) is commonly performed. There are 3 additional variants covered in this document: patients with a positive D-dimer without a high-risk clinical score (Variant 2), patients with a high pretest probability for PE (Variant 3), and pregnant patients (Variant 4). This document draws on the findings of the joint American College of Cardiology/ACR guideline on chest pain in the emergency room [9] and the American Thoracic Society/Society of Thoracic Radiology Clinical Practice Guideline: Evaluation of Suspected Pulmonary Embolism In Pregnancy [3]. Special Imaging Considerations Chest radiography is very limited in the assessment for PE, but it may diagnose a pneumothorax, pneumonia, or other condition. A chest radiograph is typically used in the interpretation of a ventilation and perfusion (V/Q) lung scan [10]. Because chest radiography is typically performed before advanced imaging is considered, it is not included in the ratings for Variants 1 through 3. aCleveland Clinic, Weston, Florida. bThe University of Texas MD Anderson Cancer Center, Houston, Texas. cPanel Chair, Cleveland Clinic, Cleveland, Ohio. dPanel Chair, Duke University, Durham, North Carolina.


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. ePanel Vice-Chair, Mayo Clinic, Rochester, Minnesota. fUniversity of Utah, Department of Radiology and Imaging Sciences, Salt Lake City, Utah; Commission on Nuclear Medicine and Molecular Imaging. gUniversity of Iowa Hospitals and Clinics, Iowa City, Iowa. hUniversity of Michigan Health System, Ann Arbor, Michigan. iMetroHealth Medical Center, Cleveland, Ohio, Primary care physician. jMallinckrodt Institute of Radiology, Saint Louis, Missouri. kUniversity of Cincinnati, Cincinnati, Ohio. lRhode Island Hospital, Providence, Rhode Island. mJohns Hopkins University School of Medicine, Baltimore, Maryland. nUniversity of Virginia Health System, Charlottesville, Virginia; Society of Cardiovascular Computed Tomography. oDenver Health, Denver, Colorado; American College of Emergency Physicians. pVA Medical Center, University of California-Irvine, Irvine, California; Society for Cardiovascular Magnetic Resonance. qSpecialty Chair, Ohio State University Wexner Medical Center, Columbus, Ohio. rSpecialty Chair, UT Southwestern Medical Center, Dallas, Texas. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Suspected Pulmonary Embolism All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. In addition, CTPA is a named CT angiogram with intravenous (IV) contrast.


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. CTPA follows the definition of a CTA above, with the addition that the timing of the scan is tailored so that contrast enhances the pulmonary arterial system to identify potential filling defects. OR Discussion of Procedures by Variant Variant 1: Suspected pulmonary embolism. Low or intermediate pretest probability with a negative D-dimer. Initial imaging. Because this scenario is clinically important, it is presented in Variant 1 despite the fact that the literature does not support advanced imaging [12-16]. Radiographs are typically performed because the differential diagnosis is broad in this patient population. CTPA The literature does not support the use of CTPA for the evaluation of suspected PE. This is in keeping with the fact that no advanced imaging is supported for patients included in this clinical scenario [8,12-16]. CT Chest With IV Contrast The literature does not support the use of CT chest with IV contrast for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. The use of CT for alternate diagnoses is beyond the scope of this document. CT Chest Without and With IV Contrast The literature does not support the use of CT chest without and with IV contrast for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. The use of CT for alternate diagnoses is beyond the scope of this document. CT Chest Without IV Contrast The literature does not support the use of CT chest without IV contrast for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. The use of CT for alternate diagnoses is beyond the scope of this document.


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. CTA Chest With IV Contrast with CTV Lower Extremities The literature does not support the use of CTA chest with IV contrast with CT venography (CTV) lower extremities for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12- 16]. The use of CTA for alternate diagnoses is beyond the scope of this document. Suspected Pulmonary Embolism Arteriography Pulmonary with Right Heart Catheterization Pulmonary angiography, including right heart catheterization and measurement of pulmonary artery and right heart pressures, is almost never used as a first-line test for PE, although it had historic diagnostic use [17-19] before it was supplanted by CTPA. The overall accuracy of catheter pulmonary angiography is likely to be inferior to CTPA. The role of angiography, when therapy such as pulmonary embolectomy is performed, is not within the scope of this document. This is in keeping with evidence suggesting that advanced imaging is not supported for patients included in Variant 1 [8,12-16]. MRA Pulmonary Arteries Without and With IV Contrast The literature does not support the use of MR angiography (MRA) pulmonary arteries without and with IV contrast for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12- 16]. MRA Pulmonary Arteries Without IV Contrast The literature does not support the use of MRA pulmonary arteries without IV contrast for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. US Duplex Doppler Lower Extremity The literature does not support the use of ultrasound (US) duplex Doppler lower extremity for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16].


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. US Echocardiography Transesophageal The literature does not support the use of US echocardiography transesophageal for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. US Echocardiography Transthoracic Resting The literature does not support the use of US echocardiography transthoracic resting for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. V/Q Scan Lung The literature does not support the use of V/Q scan lung for the evaluation of suspected PE for patients with low to intermediate probability and negative D-dimer [8,12-16]. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with IV contrast to assess PE in patients with low or intermediate probability with positive D-dimer. When IV contrast is given during the CT acquisition, the study should be performed as a CTPA. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast to assess PE in patients with low or intermediate probability with positive D-dimer. When IV contrast is given during the CT acquisition, the study should be performed as a CTPA. CT Chest Without IV Contrast There is no relevant literature to support the use of CT chest without IV contrast to assess PE in patients with low or intermediate probability with positive D-dimer. CTA Chest With IV Contrast with CTV Lower Extremities Older literature shows that the field of view for CTA can be extended to include the lower extremities so that both the pulmonary arteries and the deep veins of the leg can be imaged during the same imaging session [25,26]. However, this protocol is very rarely used at present, owing to the accuracy of performing US for DVT and the increased burden of contrast and radiation for the associated extended craniocaudal field of view [27].


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. MRA Pulmonary Arteries Without IV Contrast Noncontrast MRA sequences alone for PE have been reported but remain investigational [41,43,44]. There is limited relevant literature to support the use of noncontrast MRA for suspected PE, low or intermediate pretest probability with a positive D-dimer. US Duplex Doppler Lower Extremity Compression US with Doppler flow studies are used to evaluate for peripheral DVT [45,46] and may be useful for patients who do not have a high likelihood of PE, particularly if the patient has symptoms of extremity DVT. The presence of DVT does not indicate the presence of PE, but it increases the likelihood. A negative extremity US study does not exclude PE, although it significantly decreases its likelihood [47-49]. Suspected Pulmonary Embolism will undergo CTPA to identify a filling defect in the diagnosis of PE [51]. Risk stratification for right ventricular failure when there is a positive CTPA [52-57] is commonly used, but this clinical situation (after a diagnosis of PE) is not within the scope of this document. V/Q Scan Lung The use of V/Q scans has considerably diminished with the widespread use of CTPA. Imaging protocols have evolved [10,58,59], and in some cases, perfusion imaging alone can be performed. The high negative predictive value of a normal V/Q scan has been confirmed by several studies, including a large outcome study [60]. Among the weaknesses of V/Q scanning are the high proportion of nondiagnostic results and the inability to provide an alternative diagnosis [1,58]. Abnormal regional lung perfusion may suggest the diagnosis of PE, but it is not specific. Findings require correlation with ventilation studies or other imaging. Investigators have studied single- photon emission CT (SPECT) to improve the sensitivity and specificity of V/Q scintigraphy [61].


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. The addition of CT to SPECT enables V/Q detection of conditions other than PE (such as radiation therapy induced changes, emphysema, and extrinsic vascular compression from conditions such as neoplasm or mediastinal adenopathy). However, this use remains experimental, and it is not rated as a separate imaging study. CT Chest With IV Contrast There is no relevant literature to support the use of other imaging protocols when CTPA is performed for PE. When IV contrast is given during the CT acquisition, the study should be performed as a CTPA. CT Chest Without and With IV Contrast There is no relevant literature to support CT chest without and with IV contrast for suspected PE, high pretest probability. When IV contrast is given during the CT acquisition, the study should be performed as a CTPA. CT Chest Without IV Contrast There is no relevant literature to support CT chest without IV contrast for suspected PE, high pretest probability. CTA Chest With IV Contrast with CTV Lower Extremities Older literature shows that the field of view for CTA can be extended to include the lower extremities so that both the pulmonary arteries and the deep veins of the leg can be imaged during the same imaging session [25,26]. However, this protocol is very rarely used at present, owing to the accuracy of performing US for DVT and the increased burden of contrast and radiation for the associated extended craniocaudal field of view [27]. Arteriography Pulmonary with Right Heart Catheterization Pulmonary angiography, including right heart catheterization and measurement of pulmonary artery and right heart pressures, is almost never used as a first-line test for PE, although it had historic diagnostic use [17-19] before it was supplanted by CTPA. The overall accuracy of catheter pulmonary angiography is likely to be inferior to CTPA. The role of angiography, when therapy such as pulmonary embolectomy is performed, is not within the scope of this document.


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. This invasive procedure has an estimated morbidity and mortality of 3.5% to 6% and 0.2% to 0.5%, respectively [32,33]. MRA Pulmonary Arteries Without and With IV Contrast MRA can identify emboli in the central and segmental pulmonary arteries [34-37] among patients with low or intermediate probability with positive D-dimer [38]. However, limitations were identified by the PIOPED III trial Suspected Pulmonary Embolism MRA Pulmonary Arteries Without IV Contrast Noncontrast MRA sequences alone for PE have been reported but remain investigational [43]. There is limited literature to support the use of noncontrast MRA of the pulmonary arteries for the evaluation of PE [24,34]. US Duplex Doppler Lower Extremity Compression US may be useful for patients who do not have a high likelihood of PE, particularly if the patient has symptoms of extremity DVT. Compression US with Doppler flow studies are used to evaluate for peripheral DVT. US studies include duplex Doppler with leg compression and continuous-wave Doppler [45,46]. The presence of DVT does not indicate the presence of PE, but it increases the likelihood. A negative extremity US study does not exclude PE, although it significantly decreases its likelihood [47-49]. V/Q Scan Lung The use of V/Q scans has considerably diminished with the widespread use of CTPA. Imaging protocols have evolved [10,58,59], and in some cases, perfusion imaging alone can be performed. The high negative predictive value of a normal V/Q scan has been confirmed by several studies, including a large outcome study [60]. Among the weaknesses of V/Q scanning are the high proportion of nondiagnostic results and the inability to provide alternative diagnosis [1,58]. Abnormal regional lung perfusion may suggest the diagnosis of PE, but it is not specific. Findings require correlation with ventilation studies or other imaging. Investigators have studied SPECT to improve the sensitivity and specificity of V/Q scintigraphy [61].


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. The addition of CT to SPECT enables V/Q detection of conditions other than PE (such as radiation therapy induced changes, emphysema, and extrinsic vascular compression from conditions such as neoplasm or mediastinal adenopathy). However, this use remains experimental, and it is not rated as a separate imaging study. Variant 4: Suspected pulmonary embolism. Pregnant patient. Initial imaging. Pregnancy frequently alters the diagnostic strategy for patients with clinically suspected PE, and thus it is considered as a separate variant. For guidance on pregnant patients, please refer to the Safety Considerations in Pregnant Patients section below. Suspected Pulmonary Embolism Radiography Chest Although radiographs are neither sensitive nor specific, the role in pregnancy becomes more relevant when compared to the other variants. The rationale is that an alternative diagnosis may be found, and for patients without clinical evidence of lower extremity DVT, radiography can inform the choice between CTPA and V/Q scanning as a second imaging test. CTPA Although the CTPA acquisition may be modified [62-64] for the physiology of pregnancy, CTPA is commonly performed. In a study involving pregnant women with high pretest probability and those with intermediate probability and positive D-dimer followed by negative bilateral lower extremity US who were evaluated with CTPA, the positive rate was 5.7% (19 of 332), and the indeterminate rate was 6.9% (23 of 332) [65]. CT Chest With IV Contrast When IV contrast is given during the CT acquisition, the study should be performed as a CTPA. There is no relevant literature to support the use of CT chest with IV contrast for suspected PE in a pregnant patient. CT Chest Without and With IV Contrast When IV contrast is given during the CT acquisition, the preferred protocol is CTPA. There is no relevant literature to support the use of CT chest without and with IV contrast for suspected PE in a pregnant patient.


Suspected Pulmonary Embolism PCAs

Suspected Pulmonary Embolism PCAs. CT Chest Without IV Contrast There is no relevant literature to support the use of CT chest without IV contrast for suspected PE in a pregnant patient. CTA Chest With IV Contrast with CTV Lower Extremities Older literature shows that the field of view for CTA can be extended to include the lower extremities so that both the pulmonary arteries and the deep veins of the leg can be imaged during the same imaging session [25,26]. However, this protocol is very rarely used at present, owing to the accuracy of performing US for DVT and the increased burden of contrast and radiation for the associated extended craniocaudal field of view [27]. CTA Triple Rule Out There is no relevant literature to support the use of CTA triple rule out for suspected PE in a pregnant patient. Arteriography Pulmonary with Right Heart Catheterization There is no relevant literature to support diagnostic catheterization for PE in pregnant patients. This invasive procedure has an estimated morbidity and mortality of 3.5% to 6% and 0.2% to 0.5%, respectively [32,33]. If IV contrast is used, CTPA should be performed for diagnosis. The role of catheterization in intervention is not considered in this document. MRA Pulmonary Arteries Without and With IV Contrast In general, gadolinium-based contrast agents should be administered with caution to pregnant or potentially pregnant patients [66]. Because there are alternative methods to evaluate for PE in pregnancy that have greater benefit to the patient or fetus when compared with possible but unknown risk of fetal exposure to free gadolinium ions, MRA without and with IV contrast is rarely, if ever, performed. MRA Pulmonary Arteries Without IV Contrast Noncontrast MRA sequences alone for PE have been reported but remain investigational [43]. There is limited literature to support the use of noncontrast MRA of the pulmonary arteries for the evaluation of PE, including among pregnant patients [24,34].


Acute Pyelonephritis

Acute Pyelonephritis.  Introduction/Background Acute pyelonephritis (APN) is a severe urinary tract infection (UTI) that has the potential to cause sepsis, shock, and death [1]. The annual incidence of APN is 459,000 to 1,128,000 cases in the United States and 10.5 to 25.9 million cases globally [1,2]. The term pyelonephritis implies that there is inflammation of the renal pelvis and kidney. APN often presents with signs and symptoms of both systemic inflammation (eg, fever, chills, and fatigue) and bladder inflammation (eg, urgency, dysuria, and urinary frequency) [1]. There is a surprising lack of consensus regarding diagnostic criteria, and differentiation from infections of the lower urinary tract can be difficult [1]. Clinical presentation of APN can range from mild flank pain with low-grade or no fever to septic shock, and up to 20% of patients lack bladder symptoms. In patients with flank pain or tenderness, without or with voiding symptoms, without or with fever, and with a urinalysis showing pyuria and/or bacteriuria, APN is an appropriate presumptive diagnosis [1]. In this setting, urine cultures yielding >10,000 colony-forming units of a uropathogen per milliliter of urine is the fundamental confirmatory diagnostic test. Positive blood cultures may assist with the diagnosis. In young healthy women, Escherichia coli accounts for more than 90% of APN cases [1,3]. However, in men, elderly women, and urologically compromised and institutionalized patients, less-virulent E. coli strains, gram- negative bacilli, gram-positive organisms, and candida are also common [1,4]. Risk factors for cystitis predispose to APN and include sexual activity, new sexual partner, spermicide exposure, personal or maternal history of UTIs, genetic predisposition, and diabetes mellitus [1,5]. Fortunately, <3% of cases of cystitis and asymptomatic bacteriuria progress to APN [1,6].


Acute Pyelonephritis

Acute Pyelonephritis. Factors that disrupt urinary flow such as vesicoureteral reflux, congenital urinary tract anomalies, altered bladder function, pregnancy, renal calculi, or mechanical obstruction increase the risk of developing APN [1,7,8]. In the majority of patients, uncomplicated APN is diagnosed clinically and is responsive to treatment with appropriate antibiotics [1]. In patients who are high risk or when treatment is delayed, microabscesses may coalesce to form an acute renal abscess. The renal parenchymal abscess can at times rupture into the perinephric space and lead to development of a perirenal abscess. In other cases, the infection may be confined to an obstructed collecting system causing pyonephrosis, or accumulation of purulent material in the upper urinary collecting system, that often requires decompression for treatment to be successful. Some patients are at high risk for developing complications from APN. High-risk patients include those with a prior history of pyelonephritis, a lack of response to therapy for lower UTI or for APN, diabetes, anatomic or congenital abnormalities of the urinary system, infections by treatment-resistant organisms, nosocomial infection, urolithiasis, renal obstruction, prior renal surgery, advanced age, and pregnancy; renal transplant recipients; and immunosuppressed or immunocompromised patients [1,8-10]. Pregnant patients and patients with renal transplants on immunosuppression are at elevated risk of severe complications. Imaging studies are often requested to aid with the diagnosis, identify precipitating factors, and differentiate lower UTI from renal parenchymal involvement, aUniversity of Alabama at Birmingham, Birmingham, Alabama. bPanel Chair, Northwestern University, Chicago, Illinois. cPanel Vice-Chair, UT Southwestern Medical Center, Dallas, Texas. dIndiana University, Indianapolis, Indiana; Committee on Emergency Radiology-GSER. eUT Southwestern Medical Center, Dallas, Texas. fThe University of Texas MD Anderson Cancer Center, Houston, Texas.


Acute Pyelonephritis

Acute Pyelonephritis. gUniversity of Washington, Seattle, Washington; American Urological Association. hDuke University Medical Center, Durham, North Carolina. iSwedish Medical Center, Issaquah, Washington; American College of Emergency Physicians. jThomas Jefferson University Hospital, Philadelphia, Pennsylvania. kRoswell Park Cancer Institute, Jacobs School of Medicine and Biomedical Science, Buffalo, New York. lCleveland Clinic, Cleveland, Ohio. mMedical University of South Carolina, Charleston, South Carolina; American Urological Association. nNew York University Langone Medical Center, New York, New York. oRhode Island Hospital/The Warren Alpert Medical School of Brown University, Providence, Rhode Island; Commission on Nuclear Medicine and Molecular Imaging. pUniversity of Alabama at Birmingham Medical Center, Birmingham, Alabama, Primary care physician. qSpecialty Chair, University of Alabama at Birmingham, Birmingham, Alabama. Reprint requests to: publications@acr.org Special Imaging Considerations CT urography (CTU) is an imaging study that is tailored to improve visualization of both the upper and lower urinary tracts. There is variability in the specific parameters, but it usually involves unenhanced images followed by intravenous (IV) contrast-enhanced images, including nephrographic and excretory phases acquired at least 5 minutes after contrast injection. Alternatively, a split-bolus technique uses an initial loading dose of IV contrast and then obtains a combined nephrographic-excretory phase after a second IV contrast dose; some sites include the arterial phase. CTU should use thin-slice acquisition. Reconstruction methods commonly include maximum intensity projection or 3-D volume rendering. For the purposes of this document, we make a distinction between CTU and CT abdomen and pelvis without and with IV contrast.


Acute Pyelonephritis

Acute Pyelonephritis. CT abdomen and pelvis without and with IV contrast is defined as any protocol not specifically tailored for evaluation of the upper and lower urinary tracts and without both the precontrast and excretory phases. MR urography (MRU) is also tailored to improve imaging of the urinary system. Unenhanced MRU relies upon heavily T2-weighted imaging of the intrinsic high signal intensity from urine for the evaluation of the urinary tract. IV contrast is administered to provide additional information regarding obstruction, urothelial thickening, focal lesions, and stones. A contrast-enhanced T1-weighted series should include corticomedullary, nephrographic, and excretory phase. Thin-slice acquisition and multiplanar imaging should be obtained. For the purposes of this document, we make a distinction between MRU and MRI abdomen and pelvis without and with IV contrast. MRI abdomen and pelvis without and with IV contrast is defined as any protocol not specifically tailored for evaluation of the upper and lower urinary tracts, without both the precontrast and excretory phases, and without heavily T2- weighted images of the urinary tract. OR Discussion of Procedures by Variant Variant 1: Suspected acute pyelonephritis. First-time presentation. Uncomplicated patient (eg, no history of pyelonephritis, diabetes, immune compromise, history of stones or renal obstruction, prior renal surgery, advanced age, vesicoureteral reflux, lack of response to therapy, or pregnancy). Initial imaging. CT Abdomen and Pelvis CT of the abdomen and pelvis is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [1,10,14,15]. CT imaging may be useful if symptoms persist for 72 hours [8,10,14,16]. Nearly 95% of patients with uncomplicated pyelonephritis become afebrile within 48 hours after appropriate antibiotic therapy, and nearly 100% become afebrile within 72 hours [8,14].


Acute Pyelonephritis

Acute Pyelonephritis. CT Abdomen CT of the abdomen is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [1,10,14,15]. CTU CTU is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [1,10,14,15]. Acute Pyelonephritis Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. Fluoroscopy Voiding Cystourethrography Fluoroscopy voiding cystourethrography (VCUG) is not beneficial in the initial imaging evaluation for the first- time presentation of suspected APN in an uncomplicated patient [15]. MRI Abdomen and Pelvis MRI of the abdomen and pelvis is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. MRI Abdomen MRI of the abdomen is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. MRU MRU of the abdomen and pelvis is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. Radiography Intravenous Urography Intravenous urography (IVU) is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. US Abdomen Ultrasound (US) of the abdomen is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. In addition, US had inferior accuracy for detection of APN compared with CT [10,17].


Acute Pyelonephritis

Acute Pyelonephritis. US Color Doppler Kidneys and Bladder Retroperitoneal US color doppler of the kidneys, bladder, and retroperitoneum is not beneficial in the initial imaging evaluation for the first-time presentation of suspected APN in an uncomplicated patient [15]. Variant 2 : Suspected acute pyelonephritis. Complicated patient (eg, recurrent pyelonephritis, diabetes, immune compromise, adv anced ag e, vesicoureteral reflux, or lack of response to initial therapy). Initial imaging. The goal of imaging in a complicated patient with suspected APN is to identify the presence or absence of APN and identify associated complications. Patients with a history of renal calculi are separately discussed in variant 3. CT Abdomen and Pelvis There is widespread agreement that CT of the abdomen and pelvis with IV contrast is a useful study to diagnose APN in a complicated patient without a prior history of stone disease [1,8,14-21]. CT imaging should include the pelvis for multiple reasons. For example, unsuspected urolithiasis can be in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites can be identified, and abnormalities of the urinary bladder can be detected, among other potential sources of APN. Contrast-enhanced CT can be used to detect signs of APN including focal or multifocal decreased parenchymal enhancement, complications of APN including a renal or perirenal abscess or emphysematous pyelonephritis, and underlying problems including hydronephrosis, obstructing stones, or congenital abnormalities [1,8,14,17-19]. In a retrospective study of patients with suspected APN that underwent both unenhanced and contrast-enhanced CT (n = 183), contrast-enhanced CT detected parenchymal inv olvement in 62.5% of patients, whereas unenhanced CT detected parenchymal involvement in only 1.4% of cases, and 4.6% of patients had renal abscesses that were missed on unenhanced CT and on ly detected on contrast-e nhanced CT [19] . Furthermore, un enhanced CT missed the


Acute Pyelonephritis

Acute Pyelonephritis. Acute Pyelonephritis diagnosis of acute extrarenal conditions including cholecystitis (n = 1), liver abscess (n = 1), and appendicitis (n =1), which were all subsequently diagnosed with contrast-enhanced CT [19]. In the absence of a history of renal stones, the benefit of performing unenhanced CT in combination with contrast- enhanced CT is negligible in a complicated patient with suspected APN. In a small retrospective study of adult patients with clinical and laboratory suspicion of APN who all underwent triphasic abdominal CT (n = 100), the accuracy of the nephrographic phase among 2 readers for diagnosis of APN was 90% to 92% and for diagnosis of urolithiasis was 96% to 99% [22]. There was no significant difference in the accuracy of the triphasic abdominal CT relative to the nephrographic phase only [22]. In a prospective nonrandomized data collection study of patients with a final diagnosis of APN (n = 827), the detection rate of APN was 84.4% (445/527) by abdominal CT and only 40% (72/180) by abdominal US [10]. Although the detection rate of urolithiasis and hydronephrosis were similar by abdominal CT and abdominal US, the rate of detection of renal abscess was 4.0% (21/527) by abdominal CT and only 1.1% (2/180) by US [10]. US, CT, and MRI can show evidence of chronic pyelonephritis, including renal scarring, atrophy and cortical thinning, hypertrophy of residual normal tissue, and renal asymmetry [1,8,14,15,17,19,20]. Advantages of abdominal CT and US over abdominal MRI may include superior detection of urolithiasis, and CT may be superior to US and MRI in detection of gas in emphysematous pyelonephritis [1,14,15,18]. Contrast-enhanced CT of the abdomen and pelvis is supported in high-risk or complicated patients if initial treatment is unresponsive or symptoms worsen [1,2,8,10,15,17-19]. In general, contrast-enhanced CT of the abdomen and pelvis should be delayed 72 hours after initiation of therapy [1,8,14-21].


Acute Pyelonephritis

Acute Pyelonephritis. CT Abdomen CT of the abdomen with IV contrast has high accuracy for the diagnosis of APN in a complicated patient but does not allow for a comprehensive assessment of the entire genitourinary tract [1,8,14-21]. CT imaging should include the pelvis to detect potential pelvic abnormalities including urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. CTU CTU There is insufficient evidence to support the use of CTU for detection of suspected APN in the complicated patient. There is variability in CTU imaging technique. The added benefit of an excretory phase from any CTU image acquisition protocol is likely negligible with respect to detection and characterization of APN in a complicated patient. DMSA Renal Scan According to the literature, renal scintigraphy, specifically Tc-99m DMSA scan, is not beneficial for the diagnosis of APN in adults. In contrast, renal scintigraphy is useful in the pediatric population where there is difficulty in differentiating lower UTI from APN [23]. However, differentiation of lower UTI from APN is less problematic in adults, and pediatric vesicoureteral reflux often resolves in adulthood. Furthermore, in a small prospective study of adult patients with UTIs who underwent both contrast-enhanced CT and DMSA (n = 36), CT had higher accuracy in diagnosis of APN [24]. Fluoroscopy Antegrade Pyelography Antegrade pyelography is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. Fluoroscopy Voiding Cystourethrography VCUG is commonly used to identify vesicoureteral reflux but is not beneficial in the acute setting. VCUG is usually performed after resolution of acute symptoms to assess for an underlying anatomic or congenital cause, particularly in children with recurrent febrile UTIs [25].


Acute Pyelonephritis

Acute Pyelonephritis. Adult women with predisposing factors suspicious for vesicoureteral reflux may also benefit from VCUG [26]. However, VCUG is likely of limited benefit in the acute setting. MRI Abdomen and Pelvis MRI of the abdomen without or with IV contrast may be useful for detecting and characterizing congenital anomalies of the kidneys, and imaging of the pelvis could improve detection of congenital abnormalities of the distal ureters and abnormalities of the urinary bladder. In general, MRI of the pelvis is usually not combined with MRI of the abdomen unless an MRU is being performed. Diffusion-weighted imaging (DWI) [20] and contrast- Acute Pyelonephritis enhanced MRI have similar benefits in detecting renal abnormalities [27]. Studies in adults have shown that DWI can be useful in the diagnosis of uncomplicated pyelonephritis [28-30]. APN, renal abscesses, and pyonephrosis have lower apparent diffusion coefficient (ADC) values than normal renal cortical parenchyma [28]. As such, DWI and ADC provide a viable alternative to contrast-enhanced MRI or CT [30]. Disadvantages of MRI includes relatively poor accuracy for detection of urolithiasis and relatively reduced ability to detect gas in emphysematous py elonephritis [31,32] . Similar to CT, MRI does not provide benefit early in uncomplicated cases [8,14]. MRI Abdomen MRI of the abdomen has high accuracy for the diagnosis of APN in a complicated patient but does not allow for a comprehensive assessment of the entire genitourinary tract. Failure to include the pelvis could lead to a missed opportunity to detect urolithiasis in the distal ureters or urinary bladder, congenital abnormalities of the distal ureters and abnormal ureteral insertion sites, and abnormalities of the urinary bladder, among other potential sources of APN. MRU The excretory phase of MRU does not confer additional benefit with respect to detection and characterization of APN in a complicated patient.


Acute Pyelonephritis

Acute Pyelonephritis. Studies comparing MRU with DMSA renal scintigraphy for the detection of pyelonephritis and renal scaring have shown that MRU without and with IV contrast is at least equivalent or superior to DMSA for this specific purpose [33-35]. No studies of MRU without IV contrast were identified in the literature. Radiography Abdomen and Pelvis Radiography of the abdomen and pelvis (KUB) is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. Radiography Intravenous Urography IVU is not beneficial in the imaging evaluation for suspected APN in a complicated adult patient [15]. US Abdomen Although US of the abdomen has similar accuracy to CT for detection of urolithiasis and hydronephrosis, the main disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess, but it can be performed portably and without IV contrast [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonephritis and for detection of a renal abscess is higher with contrast-enhanced US relative to unenhanced US [37,38]. In one small retrospective study of adults with APN (n = 100), the accuracy of contrast-enhanced US for detection of APN approached that of contrast-enhanced CT [39]. US Color Doppler Kidneys and Bladder Retroperitoneal US including color Doppler has been shown to increase sensitivity for detection of APN beyond grayscale US [40]. US with power Doppler has been shown to have sensitivities and specificities that approach 90% in children with APN [41,42] and may have similar results in adults. Although US has similar accuracy to CT for detection of urolithiasis and hydronephrosis, the main disadvantages of US compared with CT are a lower rate of detection of APN and renal abscess [10,36-38]. Of note, the sensitivity for detection of acute complicated pyelonep hritis and for detection of a renal abscess is higher with contrast- enhanced US relative to unenhanced US [37,38]. Variant 3: Suspected acute pyelonephritis.