Staging and Post Therapy Assessment of Head and Neck Cancer. Assessment of Head and Neck Cancer CT Head Without and with IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast as follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast as follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. CT Maxillofacial With IV Contrast There is no relevant literature to support the use of CT maxillofacial with IV contrast for the evaluation of known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. CT maxillofacial will typically not include the neck and therefore would be inadequate for the staging of regional lymphadenopathy and may not include the primary site in the hypopharynx or larynx. CT Maxillofacial Without and With IV Contrast There is no relevant literature to support the use of CT maxillofacial without and with IV contrast for the evaluation of known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. CT Maxillofacial Without IV Contrast There is no relevant literature to support the use of CT maxillofacial without IV contrast for the evaluation of known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck.


Staging and Post Therapy Assessment of Head and Neck Cancer. CT Neck With IV Contrast Although protocols vary across institutions, for the purposes of this document, CT of the neck includes coverage from the top of the frontal sinuses down to the level of the aortic arch, with thin slices, multiplanar reformats, and both soft tissue and bony algorithms. CECT of the neck allows for the detection and localization of recurrent tumor and the evaluation of regional nodal disease. CT is also used to monitor treatment changes and assess for treatment complications such as infection or osteoradionecrosis. Evaluation of the treated neck is very often complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Much like MRI, it has an overall low sensitivity and positive predictive value [123] for detecting recurrence. Posttreatment CECT has been shown to detect local failure and nodal recurrence earlier than clinical examination alone [124,125]. A reported high NPV of 97.7% suggests that CT is helpful in excluding recurrence [123]. CT imaging also allows for excellent delineation of osseous anatomy, including bony destruction that can be seen in the context of recurrence or as a complication of treatment such as in osteoradionecrosis. FDG-PET/CT confers increased sensitivity compared to CECT in detecting recurrence and confers similarly to slightly increased specificity [117,119,126-128]. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. The puffed-cheek technique, consisting of requesting that the patient inflate their cheeks with pursed lips while undergoing CT examination, allows for a greater delineation of oral cavity tumors, particularly those along the gingiva and buccal mucosa. The maneuver allows for the separation of the tumor from normal mucosa and provides a clearer picture of the size and extent of disease [40].


Staging and Post Therapy Assessment of Head and Neck Cancer. CT Neck Without and With IV Contrast There is no relevant literature to support the use of CT neck without and with IV contrast for the evaluation of known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. CT Neck Without IV Contrast There is no relevant literature to support the use of CT neck without IV contrast for the evaluation of known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. CTA Neck With IV Contrast There is no relevant literature to support the use of CTA of the neck with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, Assessment of Head and Neck Cancer or cancer of unknown primary of the head and neck. In the specific case of recurrent disease encroaching on the carotid arteries, CTA of the neck can be used to identify patients at high risk of bleeding [41]. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT allows for the assessment of treatment response and detection and localization of recurrence, regional nodal disease, and distant metastases. The evaluation of the posttreatment of the neck is complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Studies have shown FDG-PET/CT to have high sensitivity and specificity for detection of local and nodal recurrence, with a higher sensitivity and similar or higher specificity to CT or MRI of the neck [117,119,126-128]. FDG-PET/CT has a very high NPV and therefore is very accurate in excluding recurrence [129-131].


Staging and Post Therapy Assessment of Head and Neck Cancer. FDG-PET/CT has been shown to be effective in identifying subclinical recurrences in the posttreatment setting [132,133]. The presence of posttreatment inflammatory change decreases the specificity of findings on FDG-PET/CT [131,134,135]. For this reason, imaging with FDG-PET/CT should ideally occur no earlier than 12 weeks after completion of therapy [117,118] to allow for treatment effects to subside, although imaging as early as 8 weeks after therapy has been suggested [136]. Concurrent infection can similarly give false-positive findings. One study found that the combination of MRI with FDG-PET/CT has the best detection of locoregional recurrence [128]. FDG-PET/CT has been found to accurately diagnose distant metastatic disease in the posttreatment setting [19,119] and may be indicated in treated advanced stage disease because of the increased rate of distant metastases. FDG-PET/MRI Skull Base to Mid-Thigh FDG-PET/MRI is new imaging modality with a growing body of evidence demonstrating the feasibility of use for routine clinical imaging including in the response assessment and evaluation of recurrence following treatment of cancer of the head and neck with FDG-PET/MRI performing similar to FDG/PET CT [137,138]. MRA Neck With IV Contrast There is no relevant literature to support the use of MRA neck with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. MRA Neck Without and With IV Contrast There is no relevant literature to support the use of MRA neck without and with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck.


Staging and Post Therapy Assessment of Head and Neck Cancer. MRA Neck Without IV Contrast There is no relevant literature to support the use of MRA neck without IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. MRI Orbits, Face, and Neck With IV Contrast There is no relevant literature to support the use of MRI of the orbits, face, and neck with IV contrast in the follow- up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. Assessment of Head and Neck Cancer MRI Orbits, Face, and Neck Without and With IV Contrast MRI orbits, face, and neck without and with IV contrast has superior soft tissue contrast resolution, which facilitates assessment of local recurrence and can be helpful in distinguishing tumor from treatment-related change and in evaluating local tumor response.


Staging and Post Therapy Assessment of Head and Neck Cancer. Evaluation of the treated neck is complicated by significant treatment-related changes that can be difficult to differentiate from persistent disease after therapy or recurrence. MRI is less susceptible to metal artifact than CT and may perform better in the oral cavity where there can be significant artifact from dental implants. Conversely, MRI offers decreased spatial resolution compared to CT and is more susceptible to motion artifact because of longer scan times. One study found that MRI, much like CT, has low sensitivity and positive predictive value for detecting recurrence in treated oropharynx cancer but has importance in excluding recurrence with a high NPV (94%) [139]. FDG-PET/CT confers increased sensitivity compared to MRI and confers similarly to slightly increased specificity when evaluating for recurrence [43]. One study found that the combination of MRI with FDG-PET/CT has the best detection of locoregional recurrence [128]. Combined pre- and postcontrast imaging provides the best opportunity to correctly identify and delineate recurrent tumor, distinguishing it from surrounding soft tissues and treatment changes. MRI Orbits, Face, and Neck Without IV Contrast There is no relevant literature to support the use of MRI of the orbits, face, and neck without IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. Combined pre- and postcontrast imaging provides the best opportunity to identify and delineate local tumor recurrence, distinguishing it from treatment- related change and in evaluating local tumor response. The absence of IV contrast limits the ability to accurately delineate the margin and the soft tissue extent of tumor.


Staging and Post Therapy Assessment of Head and Neck Cancer. However, noncontrast MR sequences are routinely used to identify tumor recurrence and can define tumor extent, in particular marrow involvement, and are used in nodal assessment. Radiography Paranasal Sinuses There is no relevant literature to support the use of radiography of the paranasal sinuses in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck. US Neck US coupled with fine-needle aspiration and/or core-needle biopsy can be a useful tool in regional nodal evaluation following treatment of cancer of the oral cavity, oropharynx, hypopharynx, larynx, or cancer of unknown primary of the head and neck [140]. A range of sensitivities and specificities for detection of nodal disease are found in the literature, likely reflecting the highly operator dependent nature of this technique. US alone has been shown to very sensitive (77.8%-96.8%) and specific (68.75%-97%) in detecting cervical nodal metastases [47,63-65]. In the presence of bulky nodal disease, US combined with FDG-PET/CT was found to be a reliable strategy to identify patients with complete nodal response to therapy with a higher combined NPV [65]. US has been shown to perform similar to CT in detection of recurrence of head and neck squamous cell carcinomas [141] but is inherently limited by operator skill and its inability to evaluate deep neck structures. Variant 6: Treated nasopharynx cancer or EBV-associated unknown primary of the head and neck. Surveillance imaging or follow-up imaging for suspected or known recurrence. Nasopharynx cancer and EBV-associated unknown primary of the head and neck is known to be responsive to radiotherapy and, in advanced disease, the combination of radiation and chemotherapy.


Staging and Post Therapy Assessment of Head and Neck Cancer. The early accurate identification of residual or recurrent disease, distant metastases, and de-differentiation from posttreatment changes is vital in posttreatment imaging and evaluation in order to determine the need for salvage therapy for improved survival. The incidence of recurrent disease following therapy has been reported to range from 6% to 16% with around half of recurrences occurring in the first 2 years [142,143]. The presence of recurrence is associated with increased risk for distant metastatic disease, reported at 30%, with distant metastatic disease the most common cause of death after treatment in NPC [142]. Direct visualization with flexible endoscopy is considered the most sensitive method for detecting mucosal recurrence. However, submucosal and deep-seated recurrences are best identified by imaging, preferably cross- sectional imaging such as MRI or functional imaging with FDG-PET/CT. Additionally, imaging in the setting of treated NPC may be geared toward detecting complications secondary to therapy, which include but are not limited to osteoradionecrosis of the skull base, brain parenchymal radiation necrosis, and infection, among others. The Assessment of Head and Neck Cancer appropriate imaging modality to evaluate each potential suspected complication will depend on the clinical scenario and is beyond the scope of this document. Radiography Chest CXR is not considered the imaging modality of choice for the evaluation of pulmonary metastatic disease in treated nasopharynx cancer or EBV-associated unknown primary of the head and neck. Chest CT is far more sensitive in detecting pulmonary metastatic disease compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% compared to chest CT [11]. The low sensitivity may in part be due to the small size of pulmonary nodules at presentation or peripheral location, in which CXR tends to be less reliable [11].


Staging and Post Therapy Assessment of Head and Neck Cancer. The use of CXR for detection of metastases has not been shown to improve prognosis because pulmonary metastatic disease detected on CXR tends to be diagnosed at a late stage when it is not as amenable to treatment [18]. CT Chest With IV Contrast CT chest with IV contrast can accurately identify pulmonary metastasis and be used to detect thoracic nodal and skeletal metastases to ribs or vertebrae. NPC has a relatively high rate of distant metastases with the lung being the second most common site of distant disease after osseous metastases. Although FDG-PET/CT is preferred for the restaging of advanced stage NPC because it allows for simultaneous detection of metastatic disease outside the thorax, CT chest may be considered for screening of pulmonary metastatic disease. CT chest confers superior spatial localization and contrast resolution compared to radiography, allowing for the detection of small pulmonary nodules [15]. CT chest may also be indicated in patients with NPC associated with smoking and alcohol intake, increasing the risk for synchronous lung cancer. The use of IV contrast may improve detection of mediastinal and hilar adenopathy by distinguishing nodes from mediastinal vessels. There is a paucity of relevant supportive literature specifically comparing the diagnostic performance of CT chest with IV contrast and CT chest without IV contrast. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast in the evaluation of treated nasopharynx cancer or EBV-associated unknown primary of the head and neck. CT Chest Without IV Contrast CT chest without IV contrast can accurately identify pulmonary metastasis and be used to detect thoracic nodal and skeletal metastases to ribs or vertebrae. NPC has a relatively high rate of distant metastases with the lung being the second most common site of distant disease after osseous metastases.


Staging and Post Therapy Assessment of Head and Neck Cancer. Although FDG-PET/CT is preferred for the restaging of advanced stage NPC because it allows for simultaneous detection of metastatic disease outside the thorax, CT chest may be considered for the screening of pulmonary metastatic disease. CT chest confers superior spatial localization and contrast resolution compared to radiography, allowing for the detection of small pulmonary nodules [15]. CT chest may also be indicated in patients with NPC associated with smoking and alcohol intake, increasing the risk for synchronous lung cancer. The use of IV contrast may improve detection of mediastinal and hilar adenopathy by distinguishing nodes from mediastinal vessels. Noncontrast CT chest may be considered as an alternative and is part of routine clinical practice, although there is paucity of relevant supportive literature evaluating the use of CT chest without IV contrast. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. Although CT head may be able to delineate skull base and intracranial involvement, inclusion of the neck is recommended to evaluate for cervical adenopathy for staging purposes. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. CT Maxillofacial With IV Contrast There is no relevant literature to support the use of CT maxillofacial with IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. CT maxillofacial may provide


Staging and Post Therapy Assessment of Head and Neck Cancer. Assessment of Head and Neck Cancer sufficient coverage for the anatomic evaluation of the primary site. However, CT maxillofacial will typically not include evaluation of the neck and would therefore be inadequate for the staging of regional lymphadenopathy. CT Maxillofacial Without and With IV Contrast There is no relevant literature to support the use of CT maxillofacial without and with IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. CT Maxillofacial Without IV Contrast There is no relevant literature to support the use of CT maxillofacial without IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. CT Neck With IV Contrast Although protocols vary across institutions, for the purposes of this document, CT of the neck includes coverage from the top of the frontal sinuses down to the level of the aortic arch, with thin slices, multiplanar reformats, and both soft tissue and bony algorithms. CECT of the neck allows for the detection and localization of nasopharyngeal tumor, treatment response assessment, and regional nodal staging. The evaluation of the posttreatment neck is often complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. MRI confers improved soft tissue contrast over CT and is generally the preferred imaging modality for evaluating NPC recurrence. CT imaging does allow for excellent delineation of osseous anatomy, including bony destruction that can be seen in the context of recurrence or as a complication of treatment such as in osteoradionecrosis [144]. CT is also used to monitor treatment changes and assess for treatment complications such as infection. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes.


Staging and Post Therapy Assessment of Head and Neck Cancer. CT Neck Without and With IV Contrast There is no relevant literature to support the use of CT neck without and with IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. CT Neck Without IV Contrast There is no relevant literature to support the use of CT neck without IV contrast in treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. CTA Neck With IV Contrast There is no relevant literature to support the use of CTA of the neck with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. In the case of recurrent disease encroaching on the carotid arteries, CTA of the neck can be used to identify patients at high risk of bleeding [41]. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT allows for the assessment of treatment response, detection and localization of recurrence, regional nodal disease, and distant metastases in treated NPC [75,90,145-147]. The presence of posttreatment inflammatory changes decreases the specificity of FDG-PET/CT, and, for this reason, imaging ideally occurs at a minimum of 12 weeks from completion of therapy to allow for treatment effects to subside, although imaging as early as 8 weeks after therapy has been suggested [136]. Concurrent infection can similarly give false-positive findings. The high NPV of FDG-PET/CT is very useful in excluding recurrence [147]. FDG-PET/CT has demonstrated similar detection rates of local recurrence as MRI but increased specificity of imaging findings, in particular in patients with treated advanced disease [143,145,146,148].


Staging and Post Therapy Assessment of Head and Neck Cancer. Metabolic response on posttreatment FDG-PET/CT has been shown to be an independent prognostic indicator conferring improved survival [149]. FDG-PET/CT has a high sensitivity and accuracy in detecting distant metastases, including osseous and pulmonary metastases [82,87,88], the most common sites for distant metastatic disease in NPC. FDG-PET/MRI Skull Base to Mid-Thigh FDG-PET/MRI is a new imaging modality with a growing body of evidence demonstrating the feasibility of use for routine clinical imaging, including the response assessment and evaluation of recurrence following treatment of cancer of the head and neck with FDG-PET/MR performing similarly to FDG/PET CT [137,138]. Assessment of Head and Neck Cancer MRA Neck With IV Contrast There is no relevant literature to support the use of MRA neck with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. MRA Neck Without and With IV Contrast There is no relevant literature to support the use of MRA neck without and with IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. MRA Neck Without IV Contrast There is no relevant literature to support the use of MRA neck without IV contrast in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated unknown primary of the head and neck.


Staging and Post Therapy Assessment of Head and Neck Cancer. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated unknown primary of the head and neck. The coverage of MRI of the head and its associated sequences may be insufficient to completely evaluate the primary site in the nasopharynx and will not include regional nodal staging. MRI head without and with IV contrast may be used to further delineate advanced intracranial extension of disease. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated unknown primary of the head and neck. MRI Orbits, Face, and Neck With IV Contrast There is no relevant literature to support the use of MRI orbits, face, and neck with IV contrast in follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated unknown primary of the head and neck. MRI Orbits, Face, and Neck Without and With IV Contrast MRI orbits, face, and neck without and with IV contrast has superior soft tissue contrast resolution, which facilitates assessment of local recurrence, and can be helpful in distinguishing it from treatment related change and for evaluating local tumor response. The superior soft tissue contrast resolution relative to CECT is critical in distinguishing recurrence from treatment changes and in the delineation of tumor recurrence, including extension into adjacent structures such as the orbits, skull base, and intracranial compartment, and the perineural spread of disease. MRI has been reported to detect up to 27.8% of deep-seated recurrences that were occult on endoscopic evaluation [142].


Staging and Post Therapy Assessment of Head and Neck Cancer. However, posttreatment inflammatory changes, reactive mucosal change, postradiation scarring, or osteoradionecrosis may complicate MRI interpretation, and FDG-PET/CT has been shown to have increased specificity in detecting local recurrence, in particular in treated advanced disease [143,145,146,148]. Combined pre- and postcontrast imaging provides the best opportunity to correctly identify and delineate recurrence site, distinguishing it from the surrounding soft tissues and treatment changes. MRI Orbits, Face, and Neck Without IV Contrast There is no relevant literature to support the use of MRI orbits, face, and neck without IV contrast in follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated unknown primary of the head and neck. Combined pre- and postcontrast imaging provides the best opportunity to identify and delineate local tumor recurrence, distinguishing it from treatment-related change and in evaluating local tumor response. The absence of IV contrast limits the ability to accurately delineate the margin and the soft tissue extent of the tumor. However, noncontrast MR sequences are routinely used to identify tumor recurrence and can define tumor extent, in particular marrow involvement, and are used in nodal assessment. Assessment of Head and Neck Cancer Radiography Paranasal Sinuses There is no relevant literature to support the use of radiography of the paranasal sinuses in the follow-up imaging or evaluation of suspected or known recurrence of treated cancer of the nasopharynx or EBV-associated cancer of unknown primary of the head and neck. US Neck US coupled with fine-needle aspiration and/or core-needle biopsy can be a useful tool in regional nodal evaluation following treatment of NPC [140]. A range of sensitivities and specificities for detection of nodal disease are found in the literature, likely reflecting the highly operator-dependent nature of this technique.


Staging and Post Therapy Assessment of Head and Neck Cancer. US alone has been shown to very sensitive (77.8%-96.8%) and specific (68.75%-97%) in detecting cervical nodal metastases [47,63-65]. In the presence of bulky nodal disease in squamous cell carcinoma, US combined with FDG-PET/CT was found to be a reliable strategy to identify patients with complete nodal response to therapy with a higher combined NPV [65]. Variant 7: Treated cancer of the paranasal sinuses or nasal cavity. Surveillance imaging or follow-up imaging for suspected or known recurrence. Cancer of the paranasal sinuses or nasal cavity is generally treated with a combination of surgery, chemotherapy, and/or radiation therapy [117]. Despite aggressive therapy, recurrence rates may be high, estimated at up to 54% in cases of advanced head and neck squamous cell carcinomas, and these typically occur within the first 2 years following treatment [117]. Early diagnosis of recurrent disease allows for prompt treatment and for providing potential salvage options, which may portend increased survival rates [117]. However, complex posttreatment changes can distort anatomy and may interfere with the detection of subtle findings. Direct visualization with flexible endoscopy is considered the most sensitive method for detecting mucosal recurrence. However, submucosal and deep-seated recurrences are best identified by imaging, preferably cross-sectional imaging such as MRI or functional imaging with FDG-PET/CT. Imaging is also crucial for the detection of distant metastatic disease. Additionally, imaging in the setting of treated sinonasal malignancy may be geared toward detecting complications secondary to therapy, which include but are not limited to cerebrospinal fluid leaks, epistaxis, meningitis, and osteoradionecrosis of the skull base, among others. The appropriate imaging modality to evaluate each potential suspected complication will depend on the clinical scenario and is beyond the scope of this document.


Staging and Post Therapy Assessment of Head and Neck Cancer. Radiography Chest CXR is not considered the imaging modality of choice for the evaluation of pulmonary metastatic disease in treated cancer of the paranasal sinuses or nasal cavity. Chest CT is far more sensitive in detecting pulmonary metastatic disease compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% compared to chest CT [11]. The low sensitivity may in part be due to the small size of pulmonary nodules at presentation or peripheral location, in which CXR tends to be less reliable [11]. The use of CXR for detection of metastases has not been shown to improve prognosis because pulmonary metastatic disease detected on CXR tends to be diagnosed at a late stage when it is not as amenable to treatment [18]. CT Chest With IV Contrast CT chest with IV contrast can accurately identify pulmonary metastasis and be used to detect thoracic nodal and skeletal metastases to the ribs or vertebrae. Patients with recurrent head and neck squamous cell carcinoma are significantly more likely to have pulmonary metastatic disease [21,120]. Development of lung metastases is also increased in advanced stage disease [15]. CT chest confers superior spatial localization and contrast resolution when compared to radiography, allowing for the improved detection of small pulmonary nodules [15]. The use of screening CT chest in patients treated with definitive therapy have been shown to detect metastatic disease that was successfully treated with salvage therapy [121]. The rates of detection of pulmonary metastatic disease in the setting of recurrent disease for chest CT is similar to that of FDG-PET/CT [122]. The use of IV contrast allows for improved detection of mediastinal and hilar adenopathy, distinguishing nodes from mediastinal vessels and aiding in the delineation of the soft tissue extension of skeletal metastatic disease.


Staging and Post Therapy Assessment of Head and Neck Cancer. There is a paucity of relevant supportive literature specifically comparing the diagnostic performance of CT chest with IV contrast and CT chest without IV contrast. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast in the evaluation of treated cancer of the paranasal sinuses or nasal cavity. Assessment of Head and Neck Cancer CT Chest Without IV Contrast CT chest without IV contrast can accurately identify pulmonary metastasis and be used to detect thoracic nodal and skeletal metastases to the ribs or vertebrae. Patients with recurrent head and neck squamous cell carcinoma are significantly more likely to have pulmonary metastatic disease [21,120]. Development of lung metastases is also increased in advanced stage disease [15]. CT chest confers a superior spatial localization and contrast resolution compared to radiography, allowing for the improved detection of small pulmonary nodules [15]. The use of screening CT chest in patients treated with definitive therapy have been shown to detect metastatic disease that was successfully treated with salvage therapy [121]. The rates of detection of pulmonary metastatic disease in the setting of recurrent disease for chest CT is similar to that of FDG-PET/CT [122]. The use of IV contrast may improve detection of mediastinal and hilar adenopathy, distinguishing nodes from mediastinal vessels and aiding in the delineation of the soft tissue extension of the skeletal metastatic disease. Noncontrast CT chest may be considered as an alternative and is part of routine clinical practice, although there is paucity of relevant supportive literature evaluating the use of CT chest without IV contrast. CT Head With IV Contrast There is no relevant literature to support the use of CT of the head with IV contrast in the evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity.


Staging and Post Therapy Assessment of Head and Neck Cancer. CT head may provide sufficient coverage for the anatomic evaluation of the primary tumor site in the sinonasal cavity; however, inclusion of the neck is recommended to evaluate for cervical adenopathy for staging purposes. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT of the head without and with IV contrast in the evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity. CT Head Without IV Contrast There is no relevant literature to support the use of CT of the head without IV contrast in the evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity. CT Maxillofacial With IV Contrast There is no relevant literature to support the use of CT maxillofacial with IV contrast for the evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity. CT of the maxillofacial region may provide sufficient coverage for the anatomic evaluation of the primary tumor site. However, CT maxillofacial will typically not include evaluation of the neck and would therefore be inadequate for the staging of regional lymphadenopathy. CT Maxillofacial Without and With IV Contrast There is no relevant literature to support the use of CT maxillofacial without and with IV contrast for evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity. CT Maxillofacial Without IV Contrast There is no relevant literature to support the use of CT maxillofacial without IV contrast for the evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity.


Staging and Post Therapy Assessment of Head and Neck Cancer. CT Neck With IV Contrast Although protocols vary across institutions, for the purposes of this document, CT of the neck includes coverage from the top of the frontal sinuses down to the level of the aortic arch, with thin slices, multiplanar reformats, and both soft tissue and bony algorithms. CECT of the neck allows for the detection and localization of recurrent sinonasal tumors, treatment response assessment, and regional nodal staging. CT provides excellent delineation of the sinonasal skeleton and is superior to MRI in the depiction of osseous anatomy [96]. The presence of skull base foraminal widening, which can be detected on thin-section CT and reconstructions, may alert to perineural tumor spread [96]. Evaluation of the treated neck is very often complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. MRI confers improved soft tissue contrast over CT and is generally the preferred imaging modality for evaluating for sinonasal recurrence. However, CT is often used to monitor treatment changes and assess for treatment complications such as infection or osteoradionecrosis. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. Assessment of Head and Neck Cancer CT Neck Without and With IV Contrast There is no relevant literature to support the use of CT neck without and with IV contrast for evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity. CT Neck Without IV Contrast There is no relevant literature to support the use of CT neck without IV contrast for evaluation of suspected or known recurrence of treated cancer of the paranasal sinuses or nasal cavity. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes.


Staging and Post Therapy Assessment of Head and Neck Cancer. CTA Neck With IV Contrast There is no relevant literature to support the use of CTA of the neck with IV contrast in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. In the case of recurrent disease encroaching on the carotid arteries, CTA of the neck can be used to identify patients at a high risk of bleeding [41]. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT allows for the assessment of treatment response, detection, and localization of recurrence, regional nodal disease, and distant metastases in treated cancer of the paranasal sinuses or nasal cavity. Evaluation of the treated neck is very often complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. The presence of posttreatment inflammatory change decreases the specificity of findings on FDG-PET/CT [134]. For this reason, imaging with FDG-PET/CT is preferred to occur at a minimum of 12 weeks after completion of therapy to allow for treatment effects to subside [117,118], although imaging as early as 8 weeks after therapy has been suggested [136]. Concurrent infection can similarly give false- positive findings. Because of the relatively low positive predictive values of FDG-PET/CT [150], physical examination as well as complementary imaging with MRI remains of utmost importance to elucidate findings discovered on PET/CT and to determine a degree of suspicion. FDG-PET/CT has a high NPV and therefore is very helpful in excluding recurrence [150]. One study calculated an NPV of 91% of a single PET/CT examination obtained at any time after completion of therapy for head and neck squamous cell carcinoma. NPV would increase to 98% if a second scan was also found to be negative [151]. FDG-PET/CT has been found to accurately diagnose distant metastatic disease in the posttreatment setting.


Staging and Post Therapy Assessment of Head and Neck Cancer. In one series, distant metastases were detected in 27% of patients on FDG-PET/CT [102]. Of note, PET/CT is of limited value in cases in which the original tumor demonstrates poor FDG uptake. Tumors with low FDG metabolic activity result in suboptimal delineation of primary tumor recurrence, lymph node involvement, and distant disease [150]. FDG-PET/MRI Skull Base to Mid-Thigh FDG-PET/MRI is a new imaging modality with a growing body of evidence demonstrating the feasibility of use for routine clinical imaging, including the response assessment and evaluation of recurrence following treatment of cancer of the head and neck, with FDG-PET/MRI performing similarly to FDG/PET CT [137,138]. MRA Neck With IV Contrast There is no relevant literature to support the use of MRA neck with IV contrast in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. MRA Neck Without and With IV Contrast There is no relevant literature to support the use of MRA neck without and with IV contrast in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. MRA Neck Without IV Contrast There is no relevant literature to support the use of MRA neck without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head with and without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity.


Staging and Post Therapy Assessment of Head and Neck Cancer. The coverage of MRI of the head and its included sequences may be insufficient to completely evaluate the primary site in the paranasal sinuses or nasal cavity and will not include regional nodal staging. MRI head without and with IV Assessment of Head and Neck Cancer contrast may be used to further delineate advanced intracranial extension of disease and can be considered in the follow-up of advanced stage olfactory neuroblastoma, which has a known propensity for intracranial dural-based metastases. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. MRI Orbits, Face, and Neck With IV Contrast There is no relevant literature to support the use of MRI orbits, face, and neck with IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. MRI Orbits, Face, and Neck Without and With IV Contrast MRI without and with IV contrast has superior soft tissue contrast resolution, which facilitates assessment of local recurrence and can be helpful in distinguishing it from treatment-related change and in evaluating local tumor response. Perineural tumor spread is more easily recognized with MRI compared to CT, as is regional extension of tumor to neighboring structures such as the orbits, dura, and brain, and subtle marrow involvement [96]. Evaluation of the treated neck is often complicated by significant treatment-related changes that can be difficult to differentiate from persistent disease after therapy or recurrence and may require clinical examination and complementary imaging studies such as FDG-PET/CT.


Staging and Post Therapy Assessment of Head and Neck Cancer. Advanced tools, including higher-resolution imaging, diffusion-weighted and diffusion-tensor sequences, and MRI perfusion techniques such as dynamic contrast-enhanced MRI show promise in improving anatomic and functional imaging [103-105]. These tools may help to distinguish between treatment change and recurrence; however, as of now, they are not consistently used in routine clinical practice. MRI Orbits, Face, and Neck Without IV Contrast There is no relevant literature to support the use of MRI orbits, face, and neck without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. Combined pre- and postcontrast imaging provides the best opportunity to identify and delineate local tumor recurrence, distinguishing it from treatment-related change and in evaluating local tumor response. The absence of IV contrast limits the ability to accurately delineate the margins and the soft tissue extent of tumor. However, noncontrast MR sequences are routinely used to identify tumor recurrence and can define tumor extent, in particular marrow involvement, and are used in nodal assessment. Radiography Paranasal Sinuses There is no relevant literature to support the use of radiography of the paranasal sinuses in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of the paranasal sinuses or nasal cavity. US Neck US coupled with fine-needle aspiration and/or core-needle biopsy can be a useful tool in regional nodal evaluation following treatment of head and neck cancer [140]. A range of sensitivities and specificities for detection of nodal disease are found in the literature, likely reflecting the highly operator-dependent nature of this technique. US alone has been shown to very sensitive (77.8%-96.8%) and specific (68.75%-97%) in detecting cervical nodal metastases [47,63-65].


Staging and Post Therapy Assessment of Head and Neck Cancer. In the presence of bulky nodal disease in squamous cell carcinoma, US combined with FDG-PET/CT was found to be a reliable strategy to identify patients with complete nodal response to therapy, with a higher combined NPV [65]. Variant 8: Treated cancer of a major salivary gland (parotid, submandibular, and sublingual glands). Surveillance imaging or follow-up imaging for suspected or known recurrence. Physical examination and imaging surveillance following treatment of malignant neoplasms of the major salivary glands may be obscured or impeded by postoperative scarring and anatomic distortion. Furthermore, deep local recurrences and perineural tumor spread can be inaccessible to clinical assessment and may go overlooked, particularly in early stages [108]. Delayed diagnosis of tumor recurrence portends a poor prognosis and a decrease in long-term survival, independent of histologic type [108,152]. Because perineural tumor spread is common in malignant salivary gland tumors, in particular in adenoid cystic carcinoma, a complete radical resection may not always be feasible and postoperative radiotherapy may be indicated [152]. Regular follow-up is recommended following treatment of malignant salivary gland neoplasms [152]. The majority, approximately 70%, of recurrences of high-grade malignant salivary gland tumors occur in the first 3 years Assessment of Head and Neck Cancer following treatment [108], and these can be subclassified into local, regional, and distant. In a large cohort of 565 patients with salivary gland tumors followed over a 10 year period, local recurrence was reported in 13% of the cases, regional recurrence was seen in 22% of the cases, and distant metastases were documented in 33% of the patients [108]. Other studies reported distant disease in >50% of patients, with adenoid cystic carcinoma, adenocarcinoma, and carcinoma ex pleomorphic adenoma accounting for the majority of the cases [108].


Staging and Post Therapy Assessment of Head and Neck Cancer. The most common site of metastatic involvement beyond the head and neck in up to 90% of cases is the lungs. A distant second are the bones followed by the liver, brain, and other sites [108]. Radiography Chest CXR is not considered the imaging modality of choice for the evaluation of pulmonary metastatic disease in treated cancer of a major salivary gland. Chest CT is far more sensitive in detecting pulmonary metastatic disease compared to radiography [15], with the sensitivity of CXR to detect pulmonary metastatic disease reported as low as 28% compared to chest CT [11]. The low sensitivity may in part be due to the small size of pulmonary nodules at presentation or peripheral location, in which CXR tends to be less reliable [11]. The use of CXR for detection of metastases has not been shown to improve prognosis because pulmonary metastatic disease detected on CXR tends to be diagnosed at a late stage when it is not as amenable to treatment [18]. CT Chest With IV Contrast CT chest with IV contrast can accurately identify pulmonary metastasis and be used to detect thoracic nodal and skeletal metastases to the ribs or vertebrae. Pulmonary metastatic disease is the single most common site of metastatic disease beyond the head and neck in suspected or confirmed metastatic disease at follow-up. CT chest confers superior spatial localization and contrast resolution compared to radiography, allowing for the detection of small pulmonary nodules [15]. The use of IV contrast may improve detection of mediastinal and hilar adenopathy by distinguishing the nodes from mediastinal vessels. There is a paucity of relevant supportive literature specifically comparing the diagnostic performance of CT chest with IV contrast and CT chest without IV contrast. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast in the evaluation of treated cancer of a major salivary gland.


Staging and Post Therapy Assessment of Head and Neck Cancer. CT Chest Without IV Contrast CT chest without IV contrast can accurately identify pulmonary metastasis and be used to detect thoracic nodal and skeletal metastases to the ribs or vertebrae. Pulmonary metastatic disease is the single most common site of metastatic disease beyond the head and neck in suspected or confirmed metastatic disease at follow-up. CT chest confers superior spatial localization and contrast resolution compared to radiography, allowing for the detection of small pulmonary nodules [15]. The use of IV contrast may improve detection of mediastinal and hilar adenopathy by distinguishing the nodes from mediastinal vessels. Noncontrast CT chest may be considered as an alternative and is part of routine clinical practice, although there is paucity of relevant supportive literature evaluating the use of CT chest without IV contrast. CT Head With IV Contrast There is no relevant literature to support the routine use of CT of the head with IV contrast in follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT Head Without and With IV Contrast There is no relevant literature to support the routine use of CT of the head without and with IV contrast in follow- up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT Head Without IV Contrast There is no relevant literature to support the routine use of CT of the head without IV contrast in follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT Maxillofacial With IV Contrast There is no relevant literature to support the routine use of CT maxillofacial with IV contrast in follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT of the maxillofacial region may provide sufficient coverage for the anatomic evaluation of the primary tumor site.


Staging and Post Therapy Assessment of Head and Neck Cancer. However, CT maxillofacial will typically not include evaluation of the neck and would therefore be inadequate for the staging of regional lymphadenopathy. Assessment of Head and Neck Cancer CT Maxillofacial Without and With IV Contrast There is no relevant literature to support the routine use of CT maxillofacial without and with IV contrast in follow- up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT Maxillofacial Without IV Contrast There is no relevant literature to support the routine use of CT maxillofacial without IV contrast in follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT Neck With IV Contrast Although protocols vary across institutions, for the purposes of this document, CT of the neck includes coverage from the top of the frontal sinuses down to the level of the aortic arch, with thin slices, multiplanar reformats, and both soft tissue and bony algorithms. CECT of the neck allows for the detection and localization of recurrent tumor and the evaluation of regional nodal disease. CT is also used to monitor treatment changes and assess for treatment complications such as infection or osteoradionecrosis. Evaluation of the treated neck is very often complicated by significant treatment related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Soft tissue resolution of CT is considered inferior to that of MRI [108], and certain cancers such as adenoid cystic carcinoma, mucoepidermoid carcinoma, and acinic cell carcinomas may lack significant contrast enhancement on CT, rendering the detection of recurrence difficult by this modality [111]. Furthermore, MRI is considered superior in the detection of perineural spread and the soft tissue extent of disease [107,108].


Staging and Post Therapy Assessment of Head and Neck Cancer. Generally, CT is reserved for the evaluation of treatment complications or when there are indeterminate findings regarding osseous invasion [107,108]. CT may prove to be especially useful in the setting of suspected bone involvement because of its improved detection of cortical erosion [112]. The use of IV contrast is recommended to better outline the extent of the primary site. CT Neck Without and With IV Contrast There is no relevant literature to support the routine use of CT neck without and with IV contrast in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. CT Neck Without IV Contrast There is no relevant literature to support the routine use of CT neck without IV contrast in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. Contrast enhancement is imperative in order to correctly identify and delineate recurrence, distinguishing it from treatment changes. CTA Neck With IV Contrast There is no relevant literature to support the routine use of CTA of the neck with IV contrast in the follow-up imaging or evaluation of known or suspected recurrence of treated cancer of a major salivary gland. In the case of recurrent disease encroaching on the carotid arteries, CTA of the neck can be used to identify patients at high risk of bleeding [41]. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT allows for the assessment of treatment response and detection and localization of recurrence, regional nodal disease, and distant metastases. The utility of FDG-PET/CT depends on the tumor grade, because low-grade salivary gland tumors tend to have relatively low metabolism and may be occult on FDG-PET/imaging. FDG- PET/CT is therefore not routinely recommended for follow-up of low-grade salivary gland tumors [108]. The presence of posttreatment inflammatory change decreases the specificity of findings on FDG-PET/CT.


Staging and Post Therapy Assessment of Head and Neck Cancer. For this reason, imaging with FDG-PET/CT should be delayed at least 8 weeks following therapy and is preferred to occur at a minimum of 12 weeks after completion of therapy to allow for treatment effects to subside [110]. Concurrent infection can similarity give false positive findings. The use of FDG-PET/CT to evaluate for local recurrence may not confer benefit over CECT and MRI [153] but may have benefit in follow-up imaging of high-grade salivary gland tumors because of the increased frequency of distant metastases [108,114]. FDG-PET/MRI Skull Base to Mid-Thigh FDG-PET/MRI is new imaging modality with a growing body of evidence demonstrating the feasibility of use for routine clinical imaging, including the initial staging of major salivary gland tumor, with FDG-PET/MRI performing similarly to FDG-PET/CT. A study comparing FDG-PET/MRI to MRI concluded that FDG-PET/MRI is superior to MRI alone in the detection of local disease recurrence and locoregional nodal metastases in patients with adenoid cystic carcinoma [152]. Also, hybrid FDG-PET/MRI was found to be superior to conventional MRI in its NPV [137]. A separate study suggests FDG-PET/MRI is superior to PET/CT in the setting of salivary gland Assessment of Head and Neck Cancer tumors because of its improved characterization of internal tumor features and because of the propensity of these malignancies to present with perineural tumor spread [154]. MRA Neck With IV Contrast There is no relevant literature to support the routine use of MRA of the head with IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. MRA Neck Without and With IV Contrast There is no relevant literature to support the routine use of MRA of the head with and without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland.


Staging and Post Therapy Assessment of Head and Neck Cancer. MRA Neck Without IV Contrast There is no relevant literature to support the routine use of MRA of the head without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. MRI Head With IV Contrast There is no relevant literature to support the routine use of MRI of the head with IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. MRI Head Without and With IV Contrast There is no relevant literature to support the routine use of MRI of the head with and without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. MRI Head Without IV Contrast There is no relevant literature to support the routine use of MRI of the head without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. MRI Orbits, Face, and Neck With IV Contrast There is no relevant literature to support the routine use of MRI orbits, face, and neck with IV contrast in the follow- up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. MRI Orbits, Face, and Neck Without and With IV Contrast MRI orbits, face, and neck without and with IV contrast has superior soft tissue contrast resolution, which facilitates assessment of local recurrence and can be helpful in distinguishing from treatment-related changes and evaluating local tumor response. Evaluation of the treated neck is very often complicated by significant treatment-related changes that can be difficult to differentiate from persistent disease after therapy or recurrence. Because of the superior soft tissue contrast resolution of MRI, it is considered the modality of choice over CECT for imaging of suspected locoregional tumor recurrence.


Staging and Post Therapy Assessment of Head and Neck Cancer. MRI better delineates the soft tissue extension of tumor, including perineural spread of disease. The use of advanced MRI techniques such as diffusion-weighted imaging may provide further information and increase sensitivity of identifying the recurrent tumor [108]. Combined pre- and postcontrast imaging provides the best opportunity to correctly identify and delineate recurrence and distinguish that from treatment change. MRI Orbits, Face, and Neck Without IV Contrast There is no relevant literature to support the routine use of MRI orbits, face, and neck without IV contrast in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. Combined pre- and postcontrast imaging provides the best opportunity to identify and delineate local tumor recurrence, distinguishing it from treatment-related change, and in evaluating local tumor response. The absence of IV contrast limits the ability to accurately delineate the margins and the soft tissue extent of the tumor. However, noncontrast MR sequences are routinely used to identify tumor recurrence and can define tumor extent, in particular marrow involvement, and are used in nodal assessment. Radiography Paranasal Sinuses There is no relevant literature to support the use of radiography of the paranasal sinuses in the follow-up imaging or the evaluation of known or suspected recurrence of treated cancer of a major salivary gland. US Neck US allows for the detection and localization of recurrence following treatment of major salivary gland tumors as well as regional nodal staging. US can additionally serve as guidance for fine-needle aspiration for diagnosis of recurrent disease [108]. Evaluation of the treated neck is complicated by significant treatment-related changes that can be difficult to distinguish from persistent disease after therapy or recurrence. Furthermore, US has limited


Epigastric Pain

Epigastric Pain.  OR Discussion of Procedures by Variant Variant 1: Epigastric pain with clinical suspicion for acid reflux or esophagitis or gastritis or peptic ulcer or duodenal ulcer. Initial imaging. GERD is a common medical disorder in the western world; it is reported that as many as 7% of Americans have episodes of heartburn every day and approximately 42% experience heartburn at least once a month [6]. Although GERD is a common disorder, its diagnosis is not straightforward; the primary reason for this is that the symptoms aNew York University Langone Medical Center, New York, New York and UT Southwestern Medical Center, Dallas, Texas. bJohns Hopkins Hospital, Baltimore, Maryland. cPanel Chair, Johns Hopkins University School of Medicine, Baltimore, Maryland. dPanel Vice-Chair, University of Alabama Medical Center, Birmingham, Alabama. eUniversity of Arizona, Banner University Medical Center, Tucson, Arizona. fDuke University Medical Center, Durham, North Carolina. gOregon Health & Science University, Portland, Oregon. hUMass Medical School, Worcester, Massachusetts. iEmory University, Atlanta, Georgia. jStanford University Medical Center, Stanford, California. kMontefiore Medical Center, Bronx, New York. lNorthwestern University Feinberg School of Medicine, Chicago, Illinois, Primary care physician. mUniversity of Connecticut, Farmington, Connecticut. nNorthShore University HealthSystem, Evanston, Illinois. oUniversity of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; American College of Emergency Physicians. pUniversity of Cincinnati Medical Center, Cincinnati, Ohio. qThe University of Mississippi Medical Center, Jackson, Mississippi; American College of Physicians. rThe Ohio State University Wexner Medical Center, Columbus, Ohio. sPhoenix Indian Medical Center, Phoenix, Arizona; American College of Surgeons. tSpecialty Chair, Virginia Commonwealth University Medical Center, Richmond, Virginia.


Epigastric Pain

Epigastric Pain. 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 Epigastric Pain are nonspecific and overlap with other conditions [6]. GERD questionnaires, esophageal manometry, esophageal pH testing, imaging examinations, and upper endoscopy are routinely used for diagnosis [6]. PUD has an incidence of 0.1% to 0.3% [7]. Early diagnosis, treatment of Helicobacter pylori infections, and widespread use of proton pump inhibitors have all led to reducing the prevalence of PUD. It is still important to diagnose PUD, because PUD-related complications can be seen in 2% to 10% of cases, and PUD-related perforation is a surgical emergency with a mortality rate of up to 30% [7,8]. Although endoscopy is considered the standard test of choice for diagnosing these entities, patients may present with nonspecific symptoms, which may lead to an imaging study in which these entities could be identified. CT Abdomen and Pelvis Although a CT examination is not the test of choice for initial imaging if acid reflux, esophagitis, gastritis, peptic ulcer, or duodenal ulcer is strongly suspected, patients with these entities may present with nonspecific/overlapping symptoms and may undergo a CT abdomen and pelvis as the initial diagnostic test for evaluation [7].


Epigastric Pain

Epigastric Pain. Findings suggestive of the diagnosis of gastritis or PUD on CT can include the following: gastric or duodenal wall thickening due to submucosal edema; mucosal hyperenhancement or fat stranding due to inflammation; fluid along the gastroduodenal region; focal outpouching of the mucosa resulting from ulcerations; focal interruption of mucosal enhancement resulting from an ulcer crater eroding through the epithelial lining of the mucosal layer into the submucosal layer or muscularis propria; focal perforation of a gastric ulcer with associated free air; or gastric outlet obstruction due to edema or chronic inflammatory changes near the antrum and pylorus [7,8]. Active bleeding from a peptic ulcer can be detected when hyperdense blood products accumulate at the site of the ulcer or in the stomach/duodenal lumen or as an area of active contrast extravasation [8]. PUD is the main cause of nontraumatic gastroduodenal perforation [11]. In a study by Lee et al [11], the following features were seen with perforation: extraluminal gas (97%), fluid or fat stranding along the gastroduodenal region (89%), ascites (89%), focal wall defect and/or ulcer (84%), and wall thickening (72%). Of these features, a wall defect and/or ulcer showed a positive likelihood ratio for gastroduodenal perforation of 36.83 and wall thickening showed a positive likelihood ratio of 10.52. Combined, these two features showed 95% sensitivity and 93% specificity for localization of a site of perforation [11]. If oral contrast is administered, extraluminal contrast may be seen at the site of perforation [8].


Epigastric Pain

Epigastric Pain. When gastric disease is suspected, the CT examination should be performed with intravenous (IV) contrast (to assess for submucosal edema, mucosal hyperenhancement due to inflammation, a focal outpouching of the mucosal bowel lining resulting from the crater of the ulcer, focal interruption of mucosal enhancement resulting from the ulcer crater eroding through the epithelial lining of the mucosal layer into the submucosal layer, or muscularis propria) and a neutral oral contrast such as water or dilute barium suspension (positive oral contrast can impede assessment of mucosal enhancement and preclude assessment of intraluminal bleeding) [12]. There is limited value of performing a CT abdomen and pelvis without and with IV contrast for this indication. A CT examination without IV contrast may help in diagnosing PUD by detecting findings such as extraluminal gas, reactive fluid, fat stranding along the gastroduodenal region, ascites, focal wall defect, or a large ulcer. However, the addition of IV contrast significantly improves conspicuity of findings such as interrupted mucosal enhancement and bowel wall hyperenhancement, making the CT examination more sensitive in diagnosis. CT Abdomen Although a CT abdomen examination may provide the same clues to diagnose acid reflux, esophagitis, gastritis, peptic ulcer, or duodenal ulcer as a CT abdomen and pelvis examination, the latter is usually chosen when overlapping or nonspecific symptoms are encountered. If gastric disease is strongly suspected, it would be appropriate to omit the pelvis from the examination. When gastric disease is suspected, the CT examination should be performed with IV contrast (to assess for submucosal edema, mucosal hyperenhancement due to inflammation, a focal outpouching of the mucosal bowel Epigastric Pain


Epigastric Pain

Epigastric Pain. lining resulting from the crater of the ulcer, focal interruption of mucosal enhancement resulting from the ulcer crater eroding through the epithelial lining of the mucosal layer into the submucosal layer or muscularis propria) and neutral oral contrast such as water or dilute barium suspension (positive oral contrast can impede assessment of mucosal enhancement and preclude assessment of intraluminal bleeding) [12]. There is limited value of performing a CT abdomen without and with IV contrast for this indication. A CT examination without IV contrast may help in diagnosing PUD by detecting findings such as extraluminal gas, reactive fluid, fat stranding along the gastroduodenal region, ascites, focal wall defect, or a large ulcer. However, the addition of IV contrast significantly improves conspicuity of findings, such as interrupted mucosal enhancement and bowel wall hyperenhancement, making the CT examination more sensitive in diagnosis. CT Abdomen Multiphase Multiphase contrast-enhanced examinations are not routinely performed in patients with suspected acid reflux, esophagitis, gastritis, peptic ulcer, or duodenal ulcer, but a CT angiographic protocol, including precontrast, arterial, and portal venous phases or a 2-phase dual-energy protocol with arterial and portal venous phases, may be used for patients with suspected acute gastrointestinal (GI) bleeding. These protocols may be used if GI bleeding as a complication of PUD is suspected [12]; otherwise, there would be limited utility of a multiphase examination. FDG-PET/CT Skull Base to Mid-Thigh Although patients with GERD and esophagitis may exhibit increased radiotracer uptake in the distal esophagus on fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET [13], there is no relevant literature to support the use of FDG- PET/CT in the prospective diagnosis of acid reflux, esophagitis, gastritis, peptic ulcer, or duodenal ulcer.


Epigastric Pain

Epigastric Pain. Fluoroscopy Biphasic Esophagram Fluoroscopy continues to be an important radiologic modality for the evaluation of patients with epigastric pain due to reflux symptoms, esophagitis, or for nonspecific abdominal pain that could be due to GERD or PUD. Depending on the symptoms, the evaluation may be performed with an esophagram/barium swallow, an upper GI series, or a combination of the two. A barium swallow/esophagram can be performed as a multiphasic examination that includes upright double-contrast views with a high density barium suspension, prone single-contrast views with a low-density barium suspension, and mucosal-relief views with either density of barium suspension [14]. The double-contrast phase optimizes the ability to detect inflammatory or neoplastic diseases, whereas the single-contrast phase optimizes the ability to detect hiatal hernias and lower esophageal rings or strictures [14]. Barium esophagram provides anatomic and functional information on esophageal length, presence, and size of hiatal hernia, diverticulum, esophageal stricture, as well as the presence of gastroesophageal reflux events with provocation [6]. Reflux esophagitis may manifest as fine nodularity or granularity of the mucosa, erosions or ulcers, thickened longitudinal folds, inflammatory esophagogastric polyps, and scarring with strictures, sacculations, or fixed transverse folds [14]. Single-contrast examinations have a reported sensitivity of 77% for detecting endoscopically proven esophagitis. Double-contrast examinations have a higher sensitivity of 80% because of their ability to reveal mucosal abnormalities that cannot be visualized on single-contrast studies. An even higher sensitivity of 88% is achieved by using a combined technique [14-16]. As such, a combined technique is most favorable for this assessment.


Epigastric Pain

Epigastric Pain. Fluoroscopy Single-Contrast Esophagram Although a biphasic examination is preferred to a single-contrast examination to assess for reflux/esophagitis, a single-contrast examination may be necessary because of patient capabilities. A single-contrast examination may be helpful by revealing reflux, lower esophageal rings, or strictures [12]. Fluoroscopy Upper GI Series The double-contrast upper GI series is a beneficial diagnostic test for evaluating structural and functional abnormalities of the esophagus, stomach, and duodenum [17]. Fluoroscopic evaluation of the esophagus may reveal findings of esophagitis as detailed above. In addition, evaluation of the stomach can be helpful in diagnosing gastritis, which may manifest as enlarged areae gastricae, disruption of the normal polygonal areae gastricae pattern by multiple uniform nodules, thickened gastric folds, erosions, or an ulcer with smooth folds radiating to the margin. In contrast, findings concerning for malignancy include an ulcer associated with nodularity of the adjacent mucosa, mass effect, or coarse, lobulated, or irregular radiating folds [17]. This examination should be performed when symptoms are nonspecific and differential possibilities of esophagitis, gastritis, or PUD are being considered. Epigastric Pain MRI Abdomen In general, MRI is not routinely used to diagnose GERD. For patients presenting with nonspecific symptoms when gastritis or peptic ulcer or duodenal ulcer is suspected, MRI may be able to suggest these diagnoses, but a CT examination is typically chosen over MRI because of its ability to detect free air associated with a perforated ulcer and its shorter time interval to obtain the examination. MRI Abdomen with MRCP There is no relevant literature to support the use of MR cholangiopancreatography (MRCP) sequences in the prospective diagnosis of acid reflux or esophagitis or gastritis or peptic ulcer or duodenal ulcer. Variant 2: Epigastric pain with clinical suspicion for gastric cancer. Initial imaging.


Epigastric Pain

Epigastric Pain. Gastric adenocarcinoma has an incidence rate of 7.3 per 100,000 with 27,600 new cases estimated in 2020 and a 5- year relative survival rate of 32% [18]. Although endoscopy with biopsy is the reference standard for diagnosing gastric cancer, patients often present with nonspecific symptoms and undergo an imaging test for workup of those symptoms; gastric cancer may be first detected on such imaging. CT Abdomen and Pelvis Although endoscopy is the reference standard for diagnosing gastric cancer, patients may present with nonspecific symptoms and may undergo an imaging test for workup of those symptoms; gastric cancer may be first detected on such imaging. Additionally, malignancy is now the most common cause of gastric outlet obstruction in adults because the incidence of PUD has decreased because of the widespread use of H2 blockers [12]. If a gastric outlet obstruction is suspected, a CT may be ordered for anatomic evaluation. In some cases, a gastric mass may not be well seen on CT because of gastric underdistension. However, multiple other imaging findings may nonetheless be identified on CT that are concerning for this diagnosis, such as nodular or irregular wall thickening or enhancement, soft tissue attenuation of wall thickening (rather than low attenuation thickening due to edema), perforation with an ulcerated mass, lymphadenopathy, and distant metastases [7,8,12]. When gastric disease is suspected, the CT examination should be performed with IV contrast (to assess for nodular wall thickening, soft tissue attenuation of the wall thickening) and neutral oral contrast such as water or dilute barium suspension to help delineate the intraluminal space [12]. There is limited value of performing a CT abdomen and pelvis without and with IV contrast for this indication. A CT abdomen and pelvis without IV contrast will be less sensitive in establishing this diagnosis [12,19].


Epigastric Pain

Epigastric Pain. CT Abdomen Although a CT abdomen examination may provide the same clues to diagnose gastric cancer as a CT abdomen and pelvis examination, the latter is usually chosen when nonspecific/overlapping symptoms are encountered. Additionally, including the pelvis may be valuable for assessing distant metastases. When gastric disease is suspected, the CT examination should be performed with IV contrast (to assess for nodular wall thickening, soft tissue attenuation of the wall thickening) and neutral oral contrast such as water or dilute barium suspension [12]. There is limited value in performing a CT abdomen without and with IV contrast for this indication. A CT abdomen without IV contrast will be less sensitive in establishing this diagnosis [12,19]. CT Abdomen Multiphase Multiphase contrast-enhanced examinations are not routinely performed in patients with gastric cancer, but a CT angiographic protocol including precontrast, arterial, and portal venous phases or a 2-phase dual-energy protocol with arterial and portal venous phases may be used for patients with suspected acute GI bleeding [12]. FDG-PET/CT Skull Base to Mid-Thigh Although patients with gastric cancer may exhibit increased radiotracer uptake at the site of malignancy on FDG- PET, there is no relevant literature to support the use of FDG-PET/CT as the test of choice for initial imaging for gastric cancer. Fluoroscopy Biphasic Esophagram A biphasic esophagram does not evaluate the stomach and hence would not be useful for initial imaging for gastric cancer. Epigastric Pain Fluoroscopy Single Contrast Esophagram A single-contrast esophagram does not evaluate the stomach, and hence would not be useful for initial imaging for gastric cancer. Fluoroscopy Upper GI Series The double-contrast upper GI series is a beneficial diagnostic test for evaluating structural and functional abnormalities of the esophagus, stomach, and duodenum [17].


Epigastric Pain

Epigastric Pain. An ulcer associated with nodularity of the adjacent mucosa, mass effect, or coarse, lobulated, or irregular radiating folds or oral contrast projecting into the mass (either inside or outside expected luminal contour) is concerning for gastric malignancy, requiring an endoscopic evaluation for a definite diagnosis [17]. Fluoroscopic examinations hold a special role in diagnosing scirrhous gastric carcinoma. Scirrhous gastric carcinomas may manifest as diffuse, long-segment, or even short-segment narrowing of a portion of the stomach. Endoscopy and biopsy have a poor sensitivity in diagnosing this entity, and a fluoroscopic examination may be essential in its diagnosis. Tumor cells invading the gastric wall result in a desmoplastic reaction that narrows the gastric lumen, making the wall rigid and nondistensible at fluoroscopy, with obliteration of gastric peristalsis [17]. MRI Abdomen Although patients with gastric cancer may exhibit nodular or irregular wall thickening or enhancement, lymphadenopathy, or distant metastases on MRI, there is no relevant literature to support the use of MRI in the prospective diagnosis of gastric cancer. MRI Abdomen with MRCP There is no relevant literature to support the use of MRCP sequences in the prospective diagnosis of gastric cancer. Variant 3: Epigastric pain with clinical suspicion for hiatal hernia. Initial imaging. In a patient with epigastric pain/discomfort and reflux symptoms, a hiatal hernia may be suspected. Hiatal hernias are reported to affect 10% to 50% of the population, with sliding hernias accounting for more than 85% of hiatal hernias and paraesophageal hernias accounting for up to 5% of all operated hiatal hernias [20]. In a relatively healthy patient with only a sliding hiatal hernia and reflux symptoms, dietary modification and a short treatment course of proton pump inhibitor may be curative with no additional testing necessary [21].


Epigastric Pain

Epigastric Pain. In a patient with longstanding/severe symptoms, the hernia may be large and/or of a paraesophageal type necessitating corrective surgery. In some cases, hiatal hernias may be associated with a shortened length of thoracic esophagus above the hernia, necessitating an esophageal lengthening procedure (eg, Collis gastroplasty) for successful treatment [21]. Size, subtype of the hernia, and severity of symptoms drive treatment, which ranges from medical management to corrective surgery [20]. CT Abdomen and Pelvis There is no relevant literature to support the use of CT abdomen and pelvis for initial imaging for hiatal hernia. CT Abdomen There is no relevant literature to support the use of CT abdomen for initial imaging for hiatal hernia. CT Abdomen Multiphase There is no relevant literature to support the use of multiphase CT for initial imaging for hiatal hernia. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT for initial imaging for hiatal hernia. Fluoroscopy Biphasic Esophagram Although endoscopy can be used to diagnose a hiatal hernia based on the site of the gastroesophageal junction and diaphragmatic impression on the esophagus, barium studies provide a more accurate depiction of the anatomic features of the hernia and also enable better determination of other factors that contribute to reflux symptoms, including the size of the hiatal hernia, opening of the gastroesophageal junction, and loss of the angle of Hiss [6,21- 23]. Barium studies also are better than endoscopy for differentiating sliding hiatal hernias from paraesophageal hernias [6]; this distinction is important because the surgical approach for treating a paraesophageal hernia is different from a sliding hiatal hernia [21,23]. The importance of imaging in this context is reflected in the Epigastric Pain


Epigastric Pain

Epigastric Pain. Esophageal Diagnostic Advisory Panel Consensus of the American College of Surgeons, which states that all patients who are considered for antireflux surgery require a barium esophagram [6]. A biphasic esophagram can be useful for this indication. In addition to detecting the presence and size of a hiatal hernia, the esophagram will provide anatomic and functional information on esophageal length, esophageal stricture, presence of gastroesophageal reflux, and reflux esophagitis [6]. Reflux esophagitis may manifest as fine nodularity or granularity of the mucosa, erosions or ulcers, thickened longitudinal folds, inflammatory esophagogastric polyps, and scarring with strictures, sacculations, or fixed transverse folds [14]. Single-contrast examinations have a reported sensitivity of 77% for detecting endoscopically proven esophagitis. Double-contrast examinations have a higher sensitivity of 80% because of its ability to reveal mucosal abnormalities that cannot be visualized on single-contrast studies. An even higher sensitivity of 88% is achieved by using a combined technique [14-16]. As such, a combined technique is most favorable for this assessment. If the hiatal hernia is large, an upper GI series evaluation should be included for complete assessment of the stomach. Fluoroscopy Single Contrast Esophagram A single-contrast esophagram may be considered in some instances. Although it may not reveal the mucosal irregularity resulting from reflux disease, it may delineate the hernia, reveal reflux, lower esophageal rings, or strictures [14]. If the hiatal hernia is large, an upper GI series evaluation should be included for complete assessment of the stomach. Fluoroscopy Upper GI Series The double-contrast upper GI series is a beneficial diagnostic test for evaluating structural and functional abnormalities of the esophagus, stomach, and duodenum [17]. A double-contrast upper GI series is the most useful test for diagnosing a hiatal hernia.


Suspected Spine Trauma PCAs

Suspected Spine Trauma PCAs.  Introduction/Background Cervical Spine Imaging An estimated 3% to 4% of patients presenting to the emergency department with blunt trauma have sustained an injury to the cervical spine [1,2]. Cervical spine injuries can range from stable minor soft-tissue injuries to unstable complex injury patterns resulting in complete disruption of the cervical spine with possible neurologic or vascular injury. The wide spectrum of injury patterns can make the decision process for when to perform imaging and what type of imaging to perform challenging. Overutilization of MRI and CT imaging of the cervical spine can result in an extended emergency center visit while awaiting imaging as well as iatrogenic injuries related to prolonged cervical collar placement [3], exposure to intravenous (IV) contrast, and exposure to radiation and high-power magnetic fields. On the other hand, failure to identify an unstable cervical spine or cervical vascular injury can result in poor clinical outcomes. The National Emergency X-Radiography Utilization Study (NEXUS) and the Canadian Cervical Rules (CCR) are well-established clinical criteria for exclusion of clinically significant cervical spine injury. In their original application of the NEXUS criteria, Hoffman et al [4] found the NEXUS criteria to have a 99.6% sensitivity for detecting clinically significant cervical injury. The CCR criteria has a similar sensitivity for identifying cervical spine injury with the initial study by Stiell et al [5] that applied the CCR criteria identifying 100% of clinically significant cervical spine injuries. Since their inception, a few studies have directly compared the CCR and NEXUS criteria and have found the CCR to slightly outperform NEXUS in selecting patients at risk for cervical spine injury [6,7]. However, multiple studies have validated the sensitivity of both the NEXUS and CCR criteria for identifying clinically significant cervical spine injuries [7-12].


Suspected Spine Trauma PCAs

Suspected Spine Trauma PCAs. The ACR does not take a position on the relative merits of the two sets of criteria; however, the ACR recognizes both are in widespread clinical practice and produce concordant predictions for most patients. Thus, either NEXUS or CCR may be applied to this ACR Appropriateness Criteria document. The NEXUS criteria identify 5 clinical factors that either place patients at increased risk for cervical spine injury or limit clinical assessment of injury (Table 1). Under the NEXUS criteria, imaging evaluation of the cervical spine is not indicated if none of the 5 clinical factors are present. The strength of the NEXUS criteria is its high sensitivity (99.6%) and negative predictive value (99.9%) for identifying significant cervical spine injury [4]. However, the NEXUS criteria have very low specificity (12.9%) [4]. A patient who meets the NEXUS criteria for cervical imaging is not necessarily likely to have sustained a significant cervical spine injury. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: publications@acr.org Suspected Spine Trauma Table 1. NEXUS Criteria for Cervical Spine Imaging [4] The CCR criteria use a more complex algorithm for guiding cervical spine imaging in trauma patients than the NEXUS criteria. In the CCR criteria, patients deemed as high risk (Table 2) for cervical spine injury automatically undergo imaging evaluation of the cervical spine. Table 3. CCR Low-Risk Factors for Cervical Spine Injury [5] Simple rear-end motor vehicle crash Patient in sitting position in emergency center Patient ambulatory at any time after trauma Delayed onset of neck pain Absence of midline cervical spine tenderness


Suspected Spine Trauma PCAs

Suspected Spine Trauma PCAs. Clinical examination has a low to very low sensitivity for identifying thoracolumbar spine injuries [16-18]. Therefore, a low threshold should be maintained for screening the thoracolumbar spine with imaging in the setting of blunt trauma, particularly in older patients, who are at increased risk for spine fractures occurring in the setting of low-energy trauma, such as a fall from standing (ie, fragility fractures), which are due to diminished bone mineralization commonly present in older patient populations. A low threshold for imaging of the thoracolumbar Suspected Spine Trauma spine should also be maintained for patients with disease processes known to cause spine rigidity, such as diffuse idiopathic skeletal hyperostosis or ankylosing spondylitis. Fractures found at one level of the spine are associated with injury at other noncontiguous levels of the spine in an estimated 20% of trauma patients [26,27]. Therefore, screening of the entire cervical spine should be considered whenever an injury of the thoracolumbar spine is identified in the setting of blunt trauma. Cervical, thoracic, and lumbar spine CT reconstructions can be performed from concurrently obtained neck CT angiograms, CT imaging of the thorax, or abdomen and pelvis in trauma patients who are also imaged for suspected soft-tissue or vascular injuries, providing the same image quality as a dedicated examination without Suspected Spine Trauma CT Myelography Cervical Spine There is no role for CT myelography in the initial assessment of patients with low risk for cervical spine injury. CT Cervical Spine CT is excellent at identifying cervical spine injuries. CT is considered the gold standard for identification of cervical spine fractures, outperforming radiographs in identification of cervical spine fractures in high-, moderate- and low-risk stratifications [31]. CT is inferior to MRI in identification of many soft-tissue injuries, such as epidural hematoma, cord contusion, and ligament sprains [37-42].


Suspected Spine Trauma PCAs

Suspected Spine Trauma PCAs. However, MRI occasionally identifies cervical spine instability that was not appreciable on CT. Less than 1% of unexaminable patients will have evidence of cervical spine instability on MRI that is not appreciated on CT [40,41,43-48]. CT may be adequate for excluding clinically significant cervical spine injury in patients without neurologic symptoms even in the setting of neck tenderness [49]. CT with IV contrast does not aid in detection of cervical spine injury. CTA Head and Neck CT is the gold standard for identifying cervical spine fractures. CT during arterial phase of IV contrast administration (ie, CT angiography [CTA]) provides the added benefit of excellent visualization of arterial vasculature for assessment of arterial injury. CTA is inferior to catheter angiography in identification of cervical arterial injury [50,51]. Using catheter angiography as a gold standard, recent studies using multislice CT scanners with 16 or more detector rows have found CTA to have a reported sensitivity of 41% to 98% and specificity of 81% to 100% for identifying cervical arterial injury [43,44]. However, CTA has been shown to identify all clinically significant cervical arterial injuries [52,53], and using catheter angiography as the gold standard inherently places CTA at a disadvantage when comparing the two modalities, since catheter angiography arterial injury [50,54] is assumed to be 100% sensitive and 100% specific. CTA does expose patients to potential adverse events associated with IV contrast and can make diagnosis of subtle cervical spine fractures more challenging because of the superimposition of high attenuating contrast on the imaging field if an unenhanced examination was not performed before giving contrast. Dual-energy CT may also be utilized to remove contrast enhancement; Suspected Spine Trauma however, dual-energy CT is not widely available. CTA imaging is best reserved for patients with a high index of suspicion for cervical arterial injury.


Suspected Spine Trauma PCAs

Suspected Spine Trauma PCAs. MRI Cervical Spine MRI is generally considered inferior to CT in identifying fractures. MRI is superior to CT in identifying soft- tissue injuries of the cervical spine [37-42]. Trauma patients with negative cervical spine CT will have traumatic soft-tissue injuries identified on MRI in 5% to 24% of cases [39-41,44,45,47,48]. The identification of these soft- tissue injuries often results in extended placement of a cervical collar. However, in the absence of clinical evidence of neurologic or unstable ligament injury, MRI has a very low probability of identifying a soft-tissue injury requiring surgical treatment that is not apparent on CT [40,41,43-48,55]. Recent prospective multicenter trials suggest that MRI has a role in evaluating patients who have a negative cervical spine CT. The Western Trauma Association Multi-Institutional trial reported that CT was effective for ruling out clinically significant injury with a sensitivity of 98.5%. A small but clinically significant incidence of a missed injury was noted, and further imaging with MRI is warranted [56]. The prospective Research Consortium of New England Centers for Trauma (ReCONECT) trial studied 767 patients who had a negative cervical spine CT and went on to MRI because of cervicalgia (43.0%), inability to evaluate the cervical spine on physical examination (44.1%), or both (9.4%). MRI was abnormal in 23.6% of all patients, including ligamentous injury (16.6%), soft-tissue swelling (4.3%), vertebral disc injury (1.4%), and dural hematomas (1.3%). The patients with abnormal MRI were less likely to have their cervical collar removed than those with normal MRI (13.3% versus 88.1%). Eleven patients underwent cervical spine surgery after the MRI results. The clinical significance of these abnormal MRI findings could not be determined from this study group [55]. MRA Neck There is no role for MR angiography (MRA) in the initial assessment of patients with low risk for cervical spine injury.


Suspected Spine Trauma PCAs

Suspected Spine Trauma PCAs. Arteriography Cervicocerebral There is no role for arteriography in the initial assessment of patients with low risk for cervical spine injury. Variant 2: Age greater than or equal to 16 years. Suspected acute cervical spine blunt trauma. Imaging indicated by NEXUS or CCR clinical criteria. Initial imaging. The high sensitivity of both the NEXUS criteria and CCR for detecting significant cervical spine injury comes at a cost of both criteria having a very low specificity for significant cervical spine injury. NEXUS has a reported sensitivity of 81.2% to 99.6% with a specificity of 12.9% to 45.8% [4,11]. The original study of CCR by Stiell et al [5] reported a sensitivity of 100%, which was confirmed in later studies by Duane et al [11,12]. In head-to-head comparisons, specificity of CCR has been reported from 0.6% to 42.5% [5,7,11,12], overlapping that of the NEXUS criteria. Both of these criteria are widely used for clinical screening for cervical spine injury, and it is generally accepted that patients who do not meet either the NEXUS or CCR criteria do not require imaging evaluation for cervical spine injury. CT Myelography Cervical Spine There is no role for CT myelography in the initial assessment of patients with suspected cervical spine injury. Suspected Spine Trauma CT Cervical Spine CT is excellent at identifying cervical spine injuries. CT is considered the gold standard for identification of cervical spine fractures, outperforming radiographs in identification of cervical spine fractures in high-, moderate- and low-risk stratifications [31]. CT is inferior to MRI in identification of many soft-tissue injuries, such as epidural hematoma, cord contusion, and ligament sprains [37-42]. However, MRI occasionally identifies cervical spine instability that was not appreciable on CT. Less than 1% of unexaminable patients will have evidence of cervical spine instability on MRI that is not appreciated on CT [40,41,43-48].