Neck Imaging Reporting and Data System Category 3 on Surveillance Computed Tomography: Incidence, Biopsy Rate, and Predictive Performance in Head and Neck Squamous Cell Carcinoma

Abstract

Objectives: Neck Imaging Reporting and Data System (NI-RADS) is a radiology reporting system for head and neck cancer surveillance. Imaging findings of high suspicion for recurrence are assigned Category 3 and recommended for "Biopsy, if clinically indicated." After implementing NI-RADS for surveillance neck computed tomography (CT), our objectives are to determine the incidence of squamous cell carcinoma (SCC) Category 3 lesions in the year post-implementation, the associated biopsy rate, and the positive predictive value of NI-RADS 3 for SCC recurrence.Study Design: Retrospective cohort study. Methods: Neck CTs reported with NI-RADS between February 2020 and February 2021 were reviewed to identify patients undergoing surveillance for SCC assigned NI-RADS 3. Cancer recurrence, defined as positive biopsy result or treatment of clinically determined recurrence, was determined by electronic medical record review.Results: During the study period, 580 neck CTs were reported with NI-RADS, of which 39 (7%) CTs obtained in 37 unique patients (28 male, 9 female, mean age 66.6 years) formed the study cohort. Biopsies were obtained in 23 lesions (45%), of which 17 (74%) were positive for recurrent SCC. One nondiagnostic biopsy was clinically determined to represent recurrence. Of 28 (55%) lesions not biopsied, 18 (64%) were ultimately treated as clinically determined recurrence. Thus, among 51 individual NI-RADS 3 lesions (32 primary, 19 neck), 36 (71%) represented recurrence. Conclusion:The incidence of NI-RADS 3 lesions in our cohort was 7%. The biopsy rate was 45%, and the overall positive predictive value of NI-RADS 3 for recurrent SCC was 71%. Category 3 lesions are associated with substantial SCC recurrence risk and should be managed accordingly.

Diagnostic Performance of Response Assessment FDG‐PET/CECT in HNSCC Treated With Definitive Radio(chemo)therapy Using NI‐RADS

“…Twenty‐one (35.6%) patients had no clinical signs or symptoms at the time of recurrence, with a median time to clinically occult recurrence being 11.4 months suggesting the need to extend imaging surveillance beyond the first 6 months of treatment. Good predictive performance of NI‐RADS category 3 was reported from another large retrospective cohort 38 . Of the 580 neck CECT scans assessed, 39 (7%) scans in 37 unique patients were assigned NI‐RADS category 3.…”

Discordance Between Oncology Clinician–Perceived and Radiologist-Intended Meaning of the Postradiotherapy Positron Emission Tomography/Computed Tomography Freeform Report for Head and Neck Cancer

“…At our institution, a prospective quality improvement study of the implementation and initial referring physician and radiologist experience with NI-RADS demonstrated feasibility and rapid acceptance of the systematic reporting method . This systematic reporting structure also allows for further investigation into specific populations, particularly when the interpretation consists of an indeterminate or high suspicion (NI-RADS 3) result . Considering the success of this prior intervention in the standardization of surveillance neck CT imaging, we now aim to perform a similar quality-improvement implementation study on the use of a systematic PET/CT reporting system for posttreatment imaging of patients treated for HNSCC.…”