10.14639/0392-100X-N1561
Objective. Evaluate computed tomography (CT) signs that predict need for revision endoscopic sinus surgery (ESS) of chronic rhinosinusitis (CRS).Methods. CRS patients (n = 48) underwent routine sinus CT scans and baseline ESS in 2006-2011. Lund-Mackay (LM) scores and 43 other CT signs were analysed blinded from both sides. Patients filled in a questionnaire during the day of CT scanning. Follow-up data were collected from hospital records until January 2018. Associations were analysed by Fisher’s exact, Mann Whitney U, Kaplan-Meier method with logrank test and Cox’s proportional hazard model.Results. Total LM score was not significantly associated with the need for revision ESS. The best predictive model was a sum of CT signs of non-detectable anatomy of inferior/ middle turbinates, obstructed frontal recess, and previous sinus surgery. Using these CT findings, we formed a Radiological Score (RS) (min-max, 0-3 points). Having at least one RS point was significantly associated with the need for revision ESS during the average follow-up of 10.7 years (p = 0.008, Logrank test).Conclusions. We identified a radiologic score that was able to predict the need for revision ESS, which is probably useful in predicting CRS outcomes.
text/xml
1827-675X
1561
en
Sanna K. Toppila-Salmi
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
prediction
Radiological score of computed tomography scans predicts revision surgery for chronic rhinosinusitis
Text.Serial.Journal
https://www.actaitalica.it/
42
Rhinology
2022-03-07
2021-03-15
2022-03-07
2022-03-16
63-74
1
Sanna K. Toppila-Salmi
2022/03/07
10.14639/0392-100X-N1561
63
Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Haartman Institute, University of Helsinki, Helsinki, Finland
1827-675X
prediction
74
Radiological score of computed tomography scans predicts revision surgery for chronic rhinosinusitis
https://www.actaitalica.it/article/download/1561/740
42
ACTA OTORHINOLARYNGOLOGICA ITALICA 2022;42:63-74; doi: 10.14639/0392-100X-N1561




Rhinology


Radiological score of computed tomography scans
predicts revision surgery for chronic rhinosinusitis
Score radiologico della Tac in grado di predire la revisione chirurgica nei pazienti
affetti da rinosinusite cronica
Markus Lilja1,2, Anni Koskinen1,2, Anna Julkunen-Iivari3, Antti Mäkitie2, Jura Numminen4, Markus Rautiainen4,5,
Jyri P. Myller6, Antti Markkola7, Mikko Suvinen8, Mika Mäkelä1, Risto Renkonen3,9, Juha Pekkanen10,
Sanna K. Toppila-Salmi1,3
1
  Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; 2 Department of
Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland; 3 Haartman
Institute, University of Helsinki, Helsinki, Finland; 4 Department of Otorhinolaryngology, Tampere University Hospital. Tampere,
Finland; 5 Department of Otorhinolaryngology, University of Tampere, Tampere, Finland; 6 Department of Otorhinolaryngology,
Päijät-Häme Central Hospital, Lahti, Finland; 7 University of Helsinki and HUS Imaging, Helsinki, Finland; 8 Department of
Otorhinolaryngology, Tampere City Hospital, Tampere, Finland; 9 HUS Diagnostic Center, Helsinki, Finland; 10 Department of Public
Health, Univesity of Helsinki, Finland


SUMMARY
Objective. Evaluate computed tomography (CT) signs that predict need for revision endo-
scopic sinus surgery (ESS) of chronic rhinosinusitis (CRS).
Methods. CRS patients (n = 48) underwent routine sinus CT scans and baseline ESS in
2006-2011. Lund-Mackay (LM) scores and 43 other CT signs were analysed blinded from
both sides. Patients filled in a questionnaire during the day of CT scanning. Follow-up data
were collected from hospital records until January 2018. Associations were analysed by
Fisher’s exact, Mann Whitney U, Kaplan-Meier method with logrank test and Cox’s pro-
portional hazard model.
Results. Total LM score was not significantly associated with the need for revision ESS.
The best predictive model was a sum of CT signs of non-detectable anatomy of inferior/
                                                                                                    Received: March 15, 2021
middle turbinates, obstructed frontal recess, and previous sinus surgery. Using these CT
                                                                                                    Accepted: September 14, 2021
findings, we formed a Radiological Score (RS) (min-max, 0-3 points). Having at least one
RS point was significantly associated with the need for revision ESS during the average
                                                                                                    Correspondence
follow-up of 10.7 years (p = 0.008, Logrank test).
                                                                                                    Markus Lilja
Conclusion. We identified a radiologic score that was able to predict the need for revision
                                                                                                    Surgical Hospital
ESS, which is probably useful in predicting CRS outcomes.                                           Kasarmikatu 11-13, 00029 HUS, Finland
KEY WORDS: rhinosinusitis, CRSwNP, CRSsNP, computed tomography, prediction                          Tel. +35894711
                                                                                                    E-mail: markus.lilja@hus.fi

RIASSUNTO
                                                                                                      How to cite this article: Lilja M, Koskinen A,
Obiettivo. Valutare i segni della tomografia computerizzata (TC) predittivi della necessità
                                                                                                      Julkunen-Iivari A, et al. Radiological score of
di un intervento di revisione endoscopica dei seni paranasali (ESS) nella rinosinusite cro-           computed tomography scans predicts revision
nica (CRS).                                                                                           surgery of chronic rhinosinusitis. Acta Otorhi-
Metodi. I pazienti con CRS (n = 48) sono stati sottoposti a TC dei seni paranasali e ESS dal          nolaryngol Ital 2022;42:63-74. https://doi.
2006 al 2011. I punteggi di Lund-Mackay (LM) e altri 43 segni TC sono stati analizzati in             org/10.14639/0392-100X-N1561
cieco. I pazienti hanno compilato un questionario di valutazione al momento dell’esecuzio-
ne della TC. Sono stati revisionati i dati di follow-up dei registri ospedalieri fino a Gennaio     © Società Italiana di Otorinolaringoiatria
2018. Le analisi sono state effettuate mediante test di Fisher, Mann Whitney U, Kaplan-             e Chirurgia Cervico-Facciale
Meier con il test di logrank e il modello di rischio proporzionale di Cox.
Risultati. Il punteggio LM totale non era significativamente associato alla necessità di revi-                     OPEN ACCESS
sione mediante ESS. Il miglior modello predittivo è risultato la somma dei seguenti reperti         This is an open access article distributed in accordance with
TC: turbinati inferiori/medi non rilevabili, recesso frontale ostruito ed esiti di precedenti in-   the CC-BY-NC-ND (Creative Commons Attribution-Non-
terventi chirurgici nasosinusali. Utilizzando questi risultati TC, abbiamo creato un punteggio      Commercial-NoDerivatives 4.0 International) license. The
                                                                                                    article can be used by giving appropriate credit and mentio-
radiologico (RS) (min-max, 0-3 punti). Un punteggio RS minimo di uno, è significativamente          ning the license, but only for non-commercial purposes and
associato alla necessità di revisione ESS durante il follow-up medio di 10,7 anni (p = 0,008,       only in the original version. For further information: https://
test di Logrank).                                                                                   creativecommons.org/licenses/by-nc-nd/4.0/deed.en




                                                                                                                                                              63
M. Lilja et al.




Conclusioni. Abbiamo identificato un punteggio radiologico in grado di prevedere la necessità di revisione ESS e quindi probabilmente utile
nel predire gli esiti della CRS.
PAROLE CHIAVE: rinosinusite, CRSwNP, CRSsNP, tomografia computerizzata, previsione



Introduction                                                           nuses and ostiomeatal complex. In a few studies, its ability
                                                                       to predict the need for revision surgery in CRS and cystic
Chronic rhinosinusitis (CRS) is a heterogeneous group of
                                                                       fibrosis has also been evaluated 8,9.
inflammatory diseases of the nose and paranasal sinuses
                                                                       The aim of this study was to evaluate the signs in baseline
lasting for at least 12 weeks 1. CRS is one of the most com-           sinonasal CT that might predict the need for revision ESS.
mon chronic adult health problems in the Western world. A
European multicentre postal questionnaire study estimated
the prevalence of CRS at 11% 2. In a recent population-                Materials and methods
based survey of adults in the United States, the prevalence            Patients
of CRS was 11.5% 3. CRS has a severe impact on quality of              This prospective cohort study was carried out at the Depart-
life, which is comparable with other chronic diseases, such            ment of Otorhinolaryngology, Tampere University Hospi-
as asthma, chronic obstructive pulmonary disease and dia-              tal (Tampere, Finland) from 2006 to 2015. We used data of
betes 1. The economic burden caused by CRS is significant              a random sample of CRS patients undergoing routine si-
and relates largely to loss of productivity, increased fre-            nus CT scanning due to CRS or its suspicion during 2006-
quency of physician appointments and medical expenses 1.               2011 10. Inclusion criteria were that the patient underwent
CRS with nasal polyps (CRSwNP) and without (CRSsNP)                    ESS within one year after sinus CT scans due to CRS and
are considered to be phenotypes of CRS with possibly dif-              that patient follow-up data (concerning the possible revi-
ferent aetiologies and pathomechanisms. In addition, there             sion ESS) was available. A new CT scan during follow-up
are inflammatory endotypes of CRS, which do not lead to                was considered only for patients who underwent revision
just one main phenotype 4.                                             surgery. Exclusion criteria were the use of either acetylsali-
Endoscopic sinus surgery (ESS) has been the most com-                  cylic desensitisation, allergen immunotherapy, or anti-IgE
mon type of surgery for CRS in patients with failed ap-                therapy prior to the sinus CT scans or during follow-up.
propriate medical treatments 1. The variation in the use of            Altogether, 48 patients were included. The decision of the
operative management in CRS might reflect a number of                  baseline and revision ESS was made by a rhinologist if
factors including both under-utilisation and over-utilisation          CRS was uncontrolled after appropriate medical therapy.
of surgery, a lack of guidelines and a lack of evidence in             The appropriate medical therapy was continued after ESS.
well-constructed randomised controlled trials. The need for
revision surgery is rather common after ESS. A large pro-              Data collection
spective cohort study has shown that approximately 20% of              Baseline data were collected by a questionnaire during the
patients responded unsatisfactorily to surgery for CRS and             same day the sinus CT was performed 10. The collected var-
required revision during five-year follow-up 5. Moreover,              iables were gender, age, allergic rhinitis (AR), asthma, pre-
the study showed that revision rate was 20.6% among the                vious nasal polyps, non-steroidal anti-inflammatory drug
patients with CRSwNP compared with 15.5% for patients                  exacerbated respiratory disease (NERD), smoking habits,
with CRSsNP. A 10-year follow-up study has shown a 17%                 previous ESS, regular use of intranasal corticosteroids, a
revision surgery rate in CRS altogether, and a 25% revision            history of ≥ 1 oral corticosteroid (OCS) course(s)/past year,
rate in CRSwNP 6. Another long-term follow-up study has                number of antibiotic courses/past 2 years and duration of
reported that 36.8% of CRSwNP patients underwent addi-                 sinonasal symptoms data contained visual analogue scale
tional revision surgery within a 12-year period after ESS 7.           (VAS) score of four symptoms (nasal obstruction, facial
Computed tomography (CT) scans are used to evaluate the                pain/pressure, postnasal drip, sense of smell) (Tab. I). Pa-
extent of pathology and the need for surgery in CRS. The               tient records were reviewed until 2018 or until death if it
characteristic findings in CRS are mucosal changes within              was earlier. The follow-up data of revision ESS and its
the ostiomeatal complex and/or sinuses. In addition, the               timepoint were used. The time interval until revision sur-
opacification of the normally aerated sinus lumen due to               gery was calculated from the date of baseline CT scan.
mucosal thickening and/or fluid content can be found. The
Lund-Mackay (LM) staging is a widely used CT-staging                   CT scans
system. It is based on the grading of opacification of si-             All patients underwent routine sinus multiple detector



64
                                                                                                                               Predictive sinus computed tomography score




Table I. Patient background factors. Baseline ESS was performed within one year after the CT scans. The groups are based on revision ESS within 5 years. P-
values by Fisher’s exact test (dichotomous variables) or Mann Whitney U test (continuous variables). Q1 = 25% percentile, Q3 = 75% percentile.
                                                                                       No revision ESS in 5       Revision ESS in 5            p-value
                                                                                               years                     years
                                                                                                        N = 40                         N=8
 Gender, n(%)                                                                   Female                27 (67.5)                     3 (37.5)                       .13
                                                                                 Male                 13 (32.5)                     5 (62.5)
 Age (years), median (Q1-Q3)                                                                       40.4 (30.2-56.1)             43.8 (35.6-50.3)                   .69
 AR, n (%)                                                                        No                  16 (42.1)                     5 (71.4)                       .23
                                                                                  Yes                 22 (57.9)                     2 (28.6)
 Asthma, n (%)                                                                    No                  27 (71.1)                     5 (71.4)                       1.0
                                                                                  Yes                 11 (28.9)                     2 (28.6)
 CRSwNP, n (%)                                                                    No                  26 (66.7)                     5 (62.5)                       1.0
                                                                                  Yes                 13 (33.3)                     3 (37.5)
 NERD, n (%)                                                                      No                  26 (83.9)                     5 (71.4)                       .59
                                                                                  Yes                  5 (16.1)                     2 (28.6)
 Current smoking, n (%)                                                           No                  28 (75.7)                     6 (71.4)                       1.0
                                                                                  Yes                  9 (24.3)                     2 (28.6)
 Previous ESS, n (%)                                                              No                  30 (76.9)                     4 (42.9)                       .19
                                                                                  Yes                  9 (23.1)                     4 (57.1)
 Regular use of intranasal corticosteroids, n (%)                                 No                   6 (15.8)                     3 (42.9)                       .13
                                                                                  Yes                 32 (84.2)                     4 (57.1)
 A history of ≥ 1 OCS course/past year, n(%)                                      No                  36 (90.0)                     5 (62.5)                       .080
                                                                                  Yes                  4 (10.0)                     3 (37.5)
 Number of antibiotic courses/past 2 years, median (Q1-Q3)                                            5 (1-7.8)                     4 (0-10)                       .64
 Duration of symptoms (years), median (Q1-Q3)                                                       5.0 (2.8-11.8)               3.5 (1.6-5.0)                     .22
AR: allergic rhinitis; CRSwNP: chronic rhinosinusitis with nasal polyps; ESS: endoscopic sinus surgery; NERD: NSAIDs exacerbated respiratory disease; NSAIDs = non-steroidal anti-
inflammatory drugs; OCS: oral corticosteroid(s). Data was missing in many variations.



CT examinations for clinical purposes. Two different                                       possibility to fill in the choice ‘not detectable’ in 30/49
CT machines were used: GE LightSpeed 16 (GE Health-                                        structures. ‘Not detectable’ was not an option in the items
care, Milwaukee, Wisconsin) and Philips Brilliance 64                                      concerning LM scoring and sinus size (hypoplasia/normal/
(Philips, Best, Netherlands). Patients were imaged in the                                  hyperplasia), Keros classification, grade of surgeon’s confi-
supine position with a kilovoltage of 120 kV and a milli-                                  dence based on images, and mucosa of nasal cavity (extent
ampere second of 100 mAs. In the GE machine, the slice                                     of oedema). ‘Not detectable’ was used, for example, when
thickness was 0.625 mm with coronal reconstructions at                                     the observer was unable to determine the structure of the
1.5 mm. In the Philips machine, the slice thickness was                                    inferior or middle turbinate (atrophy/normal/hypertrophy)
0.9 mm with coronal reconstructions at 0.9 mm. Both                                        due to lack of visualisation (polyps/partly resected turbi-
were three dimensional (3D) in nature without any gap.                                     nate) (Fig. 1).
In all cases, imaging was performed using a bone fil-
ter technique. The imaging covered the entire sinonasal                                    Data analysis
area.                                                                                      Statistical analysis was carried out using the IBM SPSS
                                                                                           Statistics 23 Statistical Software Package (SPSS Inc.,
Evaluation of CT scans                                                                     Chicago, IL, USA). The sample size calculation produced
CT scans were evaluated by an experienced head and neck                                    39 subjects, when using the ratio of controls to exposure
radiologist (AM), who filled in a form of sinonasal struc-                                 group of 0.5, an accrual interval of 5 years, follow-up af-
tures and CRS-related changes from both scans and from                                     ter the accrual interval of 7 years, a median revision-free
both sides of each patient (Tab. II) 10. All evaluated struc-                              survival time of controls of 10 years, an a relative risk =
tures had 2-5 different choices. The observer also had the                                 0.3, α = 0.05 and β = 0.8. Receiver operating characteris-



                                                                                                                                                                              65
M. Lilja et al.




Table II. Fifty variables, including 49 sinonasal structures, evaluated from sinus CT scans. All structures had 2-5 different choices. All potential variables of the
Radiological Score (RS) are displayed in blue or red. All variables that ended in the RS are displayed in red.
 1       Lund-Mackay frontal sinus                             0 normal           1 partial          2 total                                              Comment
                                                                               opacification      opacification
 2       Lund-Mackay anterior ethmoidal sinus                  0 normal           1 partial          2 total
                                                                               opacification      opacification
 3       Lund-Mackay ostiomeatal unit                            0 not                             2 occluded
                                                               occluded
 4       Lund-Mackay posterior ethmoidal sinus                 0 normal           1 partial          2 total
                                                                               opacification      opacification
 5       Lund-Mackay sphenoid sinus                            0 normal           1 partial          2 total
                                                                               opacification      opacification
 6       Lund-Mackay maxillary sinus                           0 normal           1 partial          2 total
                                                                               opacification      opacification

 7       Sinus mucosal abnormalities of frontal sinus         0 none          1 thickening        2 polypoid     3 retention     4 fluid retention         ≥ 1 sinus
                                                                                                                     cyst                                    sign
 8       Sinus mucosal abnormalities of anterior              0 none          1 thickening        2 polypoid     3 retention     4 fluid retention
         ethmoidal sinus                                                                                             cyst
 9       Sinus mucosal abnormalities of posterior             0 none          1 thickening        2 polypoid     3 retention     4 fluid retention
         ethmoidal sinus                                                                                             cyst
 10      Sinus mucosal abnormalities of shenoid sinus         0 none          1 thickening        2 polypoid     3 retention     4 fluid retention
                                                                                                                     cyst
 11      Sinus mucosal abnormalities of maxillary sinus       0 none          1 thickening        2 polypoid     3 retention     4 fluid retention
                                                                                                                     cyst
 12      Hypoplasia/normal/hyperplasia of frontal sinus      0 normal         1 hyperplasia      2 hypoplasia
 13      Hypoplasia/normal/hyperplasia of anterior           0 normal         1 hyperplasia      2 hypoplasia
         ethmoidal sinus
 14      Hypoplasia/normal/hyperplasia of posterior          0 normal         1 hyperplasia      2 hypoplasia
         ethmoidal sinus
 15      Hypoplasia/normal/hyperplasia of sphenoid           0 normal         1 hyperplasia      2 hypoplasia
         sinus
 16      Hypoplasia/normal/hyperplasia of maxillary          0 normal         1 hyperplasia      2 hypoplasia
         sinus
 17      Need for septoplasty                                  0 no              1 yes                                                               5
 18      Septal deviation obstructing middle meatus            0 no              1 yes                                                               5
 19      Septum turbinate                                      0 no              1 yes                                                               5
 20      Septum deviation                                      0 no              1 yes                                                               5
 21      Septum, crest                                         0 no              1 yes                                                               5
 22      Septum, spur                                          0 no              1 yes                                                               5
 23      Previous sinus surgery performed                      0 no              1 yes                                                               5     ≥ 1 side
 24      Infraorbital cell                                     0 no              1 yes                                                               5
 25      Paradoxical middle turbinate                          0 no              1 yes                                                               5
 26      Paradoxical superior turbinate                        0 no              1 yes                                                               5
 27      Atrophy-normal-hypertrophy of inferior              0 normal        1 hypertrophy        2 atrophy                                          5        ≥1
         turbinate                                                                                                                                          turbin.
                                                                                                                                                             sign
 28      Atrophy-normal-hypertrophy of middle                0 normal        1 hypertrophy        2 atrophy                                          5
         turbinate
 29      Pneumatised superior turbinate                        0 no           1 yes but not      2 obstructive                                       5
                                                                               obstructive
 30      Concha bullosa media                                  0 no           1 yes but not      2 obstructive                                       5
                                                                               obstructive
                                                                                                                                                         continues ▶



66
                                                                                                                        Predictive sinus computed tomography score




 Table II. Fifty variables, including 49 sinonasal structures, evaluated from sinus CT scans. All structures had 2-5 different choices. All potential variables of the
 Radiological Score (RS) are displayed in blue or red. All variables that ended in the RS are displayed in red (follows from previous page).
 31     Concha bullosa superior                                  0 no          1 yes but not      2 obstructive                                        5
                                                                                 obstructive
 32     Mucosa of pneumatised middle turbinate                   0 no        1 no opacification         2                                              5
                                                                                                  opacification
 33     Mucosa of pneumatised superior turbinate                 0 no        1 no opacification         2                                              5
                                                                                                  opacification
 34     OMC region, prominent ethmoidal bulla                    0 no               1 yes                                                              5 ≥ 1 OMC
                                                                                                                                                              sign
 35     OMC region, hiatus                                      0 open       1 partly occluded 2 occluded                                              5
 36     OMC region, infundibulum                                0 open       1 partly occluded          2                                              5
 37     OMC region, maxillary antrum                            0 open       1 partly occluded          2                                              5
 38     OMC region, superior attachment of uncinate             0 cm/             1 lamina        2 skull base                                         5
        process                                                ethmoid           papyracea
 39     OMC region, accessory maxillary sinus ostium             0 no               1 yes                                                              5
 40     OMC region, pneumatised superior attachment              0 no               1 yes                                                              5
        of uncinate process
 41     Frontal recess                                         0 normal         1 occluded                                                             5 ≥ 1 side
 42     Sphenoethmoidal recess                                 0 normal         1 occluded                                                             5 ≥ 1 side
 43     Anterior ethmoidal artery                               0 safe       1 unsafe anatomy                                                          5
                                                               anatomy
 44     Optic nerve                                             0 safe       1 unsafe anatomy                                                          5
                                                               anatomy
 45     Thickness of orbital lamina of ethmoidal bone          0 normal                               2 thin                                           5
 46     Contact to middle turbinate of orbital lamina            0 no               1 yes                                                              5
        ethmoidal bone
 47     Keros classification                                                      1 I = low           2 II =       3 III = deep
                                                                                                    moderate
 48     Grade of surgeon’s confidence based on                  0 easy          1 moderate          2 difficult
        images
 49     Mucosa of nasal cavity (extent of edema)                 0 no           1 moderate           2 total                                                ≥ 1 nasal
                                                                                  swelling          occlusion                                               mucosal
                                                                                                                                                              sign
 50     Mucosa of nasal cavity (normal-polypous)               0 normal         1 thickening       2 polypoid                                          5
5 = can’t be determined.


tic (ROC) analysis was used to identify cut-off point(s) at                           surgeries i.e. revision surgeries were analysed by the Ka-
which a variable predicts the outcome revision ESS dur-                               plan-Meier method and compared with the log-rank test.
ing the follow-up. The area under the curve (AUC) was                                 Revision-free survival was calculated from the date of the
used to obtain a probability of models that an individual                             baseline CT scans to first follow-up revision sinus surgery
will have uncontrolled CRSwNP after surgery. The most                                 and/or nasal polypectomy/death/January 2018, whichever
optimal predictor model (statistically significant AUC                                came first. Univariate Cox’s proportional hazard mod-
≥ 0.70), was entered into revision-free survival analysis
                                                                                      els for interval to second surgery were constructed with
with log-rank test (revision ESS-rate) and comparative
                                                                                      the following predictor variables: gender, age, CRSwNP,
analyses (revision ESS within 5 years). Fisher’s exact test
(2-tailed) was used to compare dichotomous patient char-                              asthma and/or NERD, AR, a history of ≥ 1 OCS course(s)/
acteristics. The Kruskal-Wallis test and Mann Whitney U                               past year, previous ESS, LM score and RS. The variables
test was used to study the comparison of the continuous                               with statistically significant association were entered into
variables and total LM scores of sinus CT scans. Spear-                               a Cox multivariable model. Statistical significance was set
man rank correlation test was to study correlations. The                              in all analyses at a p-value level of less than 0.05, and all
time periods between the baseline CT scans and second                                 tests were 2-tailed.



                                                                                                                                                                   67
M. Lilja et al.




Figure 1. Examples of radiologic signs that were evaluated from sinus computed tomography (CT) scans, which were routinely performed due to clinical pur-
poses. (A) Anatomical fine structures of middle turbinates are not detectable. (B) Middle and inferior turbinates are not detectable. (C) Obstructed frontal recess
on both sides. (D) Signs of previous operation (middle meatal antrostomy on both sides) and undetectable left middle turbinate. The reasons for “not detectable”
responses were poor visualisation of middle turbinate due to polypoid change or operative modification of turbinate. (E-G) Example of a patient with RS 0 score.
(H-J) Example of a patient with RS 1 score. (K-L) Example of a patient with RS 2 score. (M-O) Example of a patient with RS 3 score.



68
                                                                                                                  Predictive sinus computed tomography score




Results                                                                          surgery, which was measured by revision ESS during fol-
                                                                                 low-up (Fig. 3). The dark blue line indicates the sum model
Baseline characteristics                                                         of “signs of surgery + obstructed frontal recess + undetect-
Subject characteristics are presented in the CRS groups                          able anatomy of inferior/middle turbinate (despite what
with/without revision ESS in five years (Tab. I), with infor-                    was the reason for it)” (e.g. “Radiological Score (RS)”)
mation on age, gender, and the self-reported factors in the                      was shown to have good predictive potential (AUC > 0.74,
two CRS groups. There were no statistically significant dif-                     p = 0.019; Fig. 3) and to contain easily identifiable vari-
ferences between the revision and non-revision groups. The                       ables, and thus it was selected for further analyses. In ROC
baseline total VAS score of symptoms or total LM score of                        analysis, there were three other significant sum algorithms
sinus CT scans were not significantly associated with the                        with good AUC levels (Fig. 3), yet they were more com-
need for revision ESS (Fig. 2A-B).                                               plex in the number and quality of signs needed, and thus
                                                                                 they were considered to not be clinically superior to the RS.
Baseline sinus CT findings                                                       None of the individual CT scans signs had a good potential
Cut-off values of continuous variables and dichotomous                           to predict the need for revision ESS (Fig. 3, AUC < 0.67).
variables of the CT scan form were identified and created                        Figure 4 demonstrates formation of RS from CT scan signs
by using comparison analyses and ROC analysis (data not                          of surgery, frontal recess and turbinates. RS was formed
shown). AUC was used to obtain a probability of model                            as the total sum of 1) non-detectable anatomy of inferior/
that an individual will have uncontrolled CRSwNP after                           middle turbinate on at least one side, ≥ 1 finding, 1 point;
                                                                                 2) obstructed frontal recess on at least one side ≥ 1 finding,
                                                                                 1 point; and 3) previous sinus surgery on at least one side,
                                                                                 1 point. Examples of the findings of the RS are shown in
                                                                                 Figure 1. The total RS value ranged between 0-3 and values
                                                                                 ≥ 1 were significantly associated with revision ESS with a
                                                                                 5-year follow-up (Fig. 4).




                                                                                 Figure 3. The receiver operating characteristic (ROC) curve plots for predic-
                                                                                 tor models of baseline factors, in order to show how the radiological score was
                                                                                 formed from the variables. The figure summarises the overall picture of dif-
                                                                                 ferent variables, and provides the possibility to compare predication potential
                                                                                 of different variables. Area under the ROC curve (AUC) was used to obtain a
                                                                                 model of probability that an individual will have uncontrolled chronic rhinosi-
Figure 2. Comparison of (A). Total VAS score of symptoms (nasal obstruction,     nusitis (CRS) after surgery. Several individual and combined variables were
facial pain/pressure, postnasal drip, sense of smell) (B). Total Lund-Mackay     tested. The number of subjects was 38 in each curve. The dark blue line indi-
scores of sinus computed tomography (CT) scans in the chronic rhinosinusitis     cates the sum model of “signs of surgery + obstructed frontal recess + unde-
(CRS) patient groups who did or did not undergo revision ESS. All patients un-   tectable anatomy of inferior/middle turbinate” (e.g. “Radiological Score (RS)”)
derwent baseline ESS performed within one year after the CT scans. P-values      was showing to have good predictive potential and to contain easily identifi-
by Mann Whitney U test.                                                          able variables, and thus it was selected for further analyses. * p value < 0.05.



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M. Lilja et al.




Figure 4. The proportion of different signs (Y-axis) in sinus computed tomography (CT) scans in chronic rhinosinusitis (CRS) patients with or without a revision
ESS in 5 years. (A) Paradoxical inferior/middle turbinate on both sides. (B) Pooled score of other structural/mucosal turbinate abnormalities than paradoxical in-
ferior/middle turbinate on both sides. (C) Obstruction of at least one frontal recess. (D) Signs of at least one previous surgery. (E) Pooled score of the questions A
and B of inferior turbinates on both sides. Difficulty in detecting the anatomy of inferior turbinate on at least one side (no, yes)? (F) Pooled score of the questions
A and B of middle turbinates on both sides. Difficulty in detecting the anatomy of middle turbinate on at least one side (no, yes)? (G) Radiological Score (RS) that
was assessed from scores (C-F) as follows; C) = 1 point, D) = 1 point, E-F) at least one “yes” = 1 point. RS is ranging between 0-3 H) Pooled RS 0 point; 1-3
points. P-values by Fisher’s exact test.



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                                                                                                                                    Predictive sinus computed tomography score




The baseline total VAS score of symptoms, or the VAS
-scores of the four symptoms (nasal obstruction, facial
pain/pressure, postnasal drip, sense of smell), did not cor-
relate with the RS (p > 0.13, r < 0.4).

Revision-free survival analyses
The mean (min-max) follow-up time until the first event
(revision ESS /death /Jan 2018), was 7.6 (0-12) years. The
sum model RS was used to predict the time until ESS in
follow-up. RS associated significantly with the need for re-
vision ESS (Fig. 5). Cox’s proportional hazards analysis
was conducted to determine which factors had predictive
value. Of the nine possible factors, RS, a history of OCS
course and previous ESS were significantly associated with
the need for revision ESS during follow-up (Table III).
When entering these three variables in a multivariable
                                                                                               Figure 5. Predictive effect of radiological score (RS) of baseline sinus computed
model, none proved to be predictive.                                                           tomography (CT) scans to the time until the revision ESS was performed. All pa-
                                                                                               tients underwent baseline ESS within one year after the CT scans. Eight patients
Discussion                                                                                     underwent revision ESS. The predictive effect was analysed according to the Ka-
                                                                                               plan-Meier method and p-values by log rank test. ESS = endoscopic sinus surgery.
This study was carried out to evaluate whether CT scan
scores using baseline scanning would be useful to predict                                      of “signs of surgery + obstructed frontal recess + unde-
the need for revision ESS during follow-up. Early predic-                                      tectable anatomy of inferior/middle turbinate” (shortened
tion of CRS control may be help to organise follow-ups and                                     as “RS”) had a good predictive potential for uncontrolled
prevent progression of disease. We found that a sum model                                      CRSwNP, as measured by revision ESS. Therefore, our re-


Table III. Univariate and multivariable Cox’s proportional hazard models for the analyzed background variables supported for the need for revision ESS. Only the
CRS subjects who underwent ESS at the baseline (n = 48) were included. Bold values denote statistical significance at the p < 0.05 level. The second model is a
multivariable model adjusted by the variables that were associated with the need for revision ESS at p < 0.05 level in the first model.
                                         N All        N (%) Events             HR (95% CI)                 p                    aHR (95% CI)             p
 Gender                   Female               30               5 (16.7)                2.29 (0.70-7.52)                 0.17                    Not entered
                           Male                18               6 (33.3)
 Age                                                                                   1.009 (0.97-1.05)                 0.66                    Not entered
 CRSwNP                     No                 31               7 (22.6)               1.06 (0.31-3.63)                  0.93                    Not entered
                            Yes                16               4 (25.0)
 Asthma and/or              No                 30               7 (23.3)                0.82 (0.21-3.18)                 0.78                    Not entered
 NERD
                            Yes                15               3 (20.0)
 AR                         No                 21               6 (28.6)                0.54 (0.15-1.91)                 0.34                    Not entered
                            Yes                24               4 (16.7)
 ≥ 1 OCS                    No                 41               7 (17.1)                3.90 (1.14-13.4)                 .031                 3.14 (0.88-11.2)                 .079
 courses/year
                            Yes                 7               4 (57.1)
 Previous ESS               No                 34               5 (14.7)               3.57 (1.09-11.71)                 .036                 2.21 (0.45-10.9)                  .33
                            Yes                13               6 (46.2)
 LM score                                                                               1.04 (0.92–1.17)                  .53                    Not entered
 Radiological                                                                           1.93 (1.07-3.50)                 .029                 1.41 (0.65-3.07)                  .39
 score
aHR: adjusted Hazard Ratio; AR: allergic rhinitis; CI: confidence interval; CRS: chronic rhinosinusitis; CRSwNP: chronic rhinosinusitis with nasal polyps; ESS: endoscopis sinus surgery;
HR: Hazard Ratio; LM: Lund-Mackay; NERD: NSAIDs exacerbated respiratory disease; NSAIDs: non-steroidal anti-inflammatory drugs; OCS:oral corticosteroid(s). Data was missing in
many variations.




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M. Lilja et al.




sults suggest that sinus CT scans taken before baseline ESS        Only a few previous studies have been published on recur-
might be used to predict the need for the revision ESS. We         rent sinus surgery using revision-free survival analysis ap-
found only one previous study evaluating the possibility to        proach. Wu et al. reviewed records of 299 CRSwNP pa-
use CT scans in the prediction of revision ESS. Hopkins et         tients who underwent two or more surgeries during 1987 to
al. have found a small but significant association between         2011 12. They found that revision surgery and regrowth of
LM score and revision surgery rates at 36 months in their          nasal polyps appear to be affected by smoking and opera-
multicentre prospective study of 1840 patients undergoing          tive technique, but not by other factors such as asthma or
surgery for CRS in the UK 8.                                       advanced CT stage. In line with this we found that a high
There were three other significant sum algorithms with             LM score of CT scans were not associated with the need
good AUC level, yet they were more complex in the num-             for revision ESS.
ber and quality of signs needed, and thus they were not            Philpott et al. investigated 1249 CRS patients and 221
considered to be clinically superior to the RS, which was          controls using a self-administered questionnaire in United
thus the only score that was selected for further analyses of      Kingdom 13. A total of 396 (57%) patients with CRSwNPs/
this study. The major reasons for rejecting other interesting      allergic fungal rhinosinusitis reported having undergone
signs were challenges in clinical identification of the signs      previous endoscopic nasal polypectomy, and 182 (46%) of
from CT scans and/or too complex algorithm due to several          them reported having undergone more than one surgery 13.
factors in the sum model. Future studies on the predictive         Mendelsohn et al. carried out a revision-free survival anal-
potential of CT scan signs by using AI-based deep learning         ysis of a cohort of 549 CRSwNP patients who underwent
tools are still important.                                         ESS over a 10-year period 14. Revision surgery occurred
Of the 49 individual signs of CT scans, the top predictors         at a high rate, especially in patients with asthma, Samter’s
were obstructed frontal recess (AUC = 0.65), and signs             triad, or frontal sinus disease. In our study, population of
of previous surgery (AUC = 0.66). However, none of the             both CRSsNP and CRSwNP patients, we were not able to
individual signs of CT scans were significantly predictive         demonstrate association between self-reported nasal poly-
for revision ESS, probably due to small sample size and/or         posis and need for revision ESS. This might reflect the fact
multiple phenotypes and radiological signs of CRS. This            that patients themselves are not aware of their nasal polyps.
could indicate that individual signs of CT scans have poor         We did not have the patient data for CRSwNP. An objec-
potential to predict uncontrolled CRS, which is a multifac-        tive indirect parameter of nasal polyps in our study was CT
torial disease with variable findings.                             signs of undetectable turbinate structure/mucosa. We found
There is growing consensus that patients with and without          that this parameter alone, however, was not associated with
polyps have distinct differences. This is reflected in the cur-    the need for revision ESS.
rent iteration of European Position Paper on Rhinosinusitis        The study by Chang CC et al. on 4484 patients who under-
and Nasal Polyps (EPOS), with different treatment algo-            went ESS for CRS showed that male patients and young
rithms for these two main phenotypes 1. It is important to         adult patients had higher revision rates 15. In addition,
recognise the progressing-disease phenotypes among pa-             Chang JE et al. found that patients with asthma or AR had
tients with early-stage CRS and to treat them actively. Di-        higher revision rates compared with patients without these
agnosis of CRS phenotypes and estimation of CRS severity           comorbidities 16. Contrary to the aforementioned studies,
are currently based on patient interview, nasal endoscopy          our previous study 17 and the current study did not find that
and sinus CT scans. Of these, only CT scans can provide            age, gender, self-reported AR, or asthma were associated
an objective scoring option for recurrent CRSwNP phe-              with the rate of revision ESS, which could be explained by
notypes. Objective scoring might be needed, for instance           the different populations and study set-ups. We did not de-
when evaluating patients with the highest need for ad-             tect that polypoid maxillary sinus mucosa affected the rate
vanced therapy (such as biological treatment) in the future.       of revision ESS. Kuiper et al. have shown in a recent study
Exposure to radiation is a clear disadvantage that decreases       that male CRS patients were 2.7 times more likely to have
the frequent use of CT in evaluating the severity of CRS. Fur-     diffuse sinus opacification than females. Asthma or hay fe-
thermore, despite technological improvements, it is known          ver also increased the risk for diffuse sinus opacification.
that there is still no safe clinically useful radiation dose for   Diffuse opacification was associated with nasal blockage
these purposes 11. Our findings on the long-term predictive        and smell loss 18. However, they did not investigate the pre-
potential of CT signs might thus have some potential for re-       dictive potential of CT signs, which could in part explain
ducing radiation exposure as well. Yet, it remains mandatory       different CT signs compared to our study.
to also develop non-radiation-related objective markers for        We acknowledge that symptoms and other factors affect
diagnostic and predictive purposes in CRS patients.                CRS control. Due to lacking data on symptoms during fol-



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                                                                                                Predictive sinus computed tomography score




low-up, we were not able to study relationships between        Ethical consideration
symptoms, radiological score and revision surgery rate.        The study was approved by the Research Ethics Committee
The limitations of this study include small sample size and    of the Pirkanmaa Hospital District (no. 96032).
a validation study with larger sample size is warranted. Re-   The research was conducted ethically, with all study pro-
vision surgery as an endpoint outcome may have been in-        cedures being performed in accordance with the require-
fluenced by several factors unrelated to recurrence of CRS,    ments of the World Medical Association’s Declaration of
including wait-times for surgery and patient preferences       Helsinki.
to delay surgery for personal reasons, operative technique,    Written informed consent was obtained from each partici-
and surgeons’ personal preferences/skills. Although elec-      pant.
tronic health records of public hospitals have shown to cov-
er 90% of all operations in Finland 19, we acknowledge that    References
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