Impact of Surveillance Imaging in Patients With HPV-Associated Oropharyngeal Carcinoma Treated With Definitive Radiation and Chemotherapy.

Objectives: Surveillance imaging for HPV-associated oropharyngeal carcinomas (OPCs) differs among physicians and institutions. Surveillance imaging can detect disease progression earlier, but can also contribute to anxiety and cost, without proven survival benefits. We sought to determine practice patterns of surveillance imaging and the number of surveillance scans needed to detect one recurrence in patients with HPV-associated OPCs.

Methods: We performed a retrospective cohort study between 2017 and 2019 (median follow-up: 39.9 mo) of consecutive patients with locally advanced HPV-associated OPC who received definitive concurrent chemoradiotherapy (CRT) with 70 Gy at a single institution. Patients were followed post-CRT and their surveillance scans were recorded. Recurrences were classified as detected by first post-treatment scans, surveillance scans, clinical exams, or incidental findings. The number of surveillance scans needed to detect 1 recurrence was determined by dividing the number of surveillance scans by the number of recurrences detected by surveillance scans.

Results: Among 276 patients with a median follow-up of 39.9 months, there were 28 recurrences. Of all recurrences, 11 (39.3%) were detected by the first post-treatment scan, 11 (39.3%) by surveillance scan, 5 (17.9%) by clinical exam, and 1 (3.6%) was incidentally found. A total of 694 surveillance scans were taken. The number of surveillance scans needed to detect 1 recurrence was 64 overall, 45 within 2 years, and 248 beyond 2 years from treatment.

Conclusions: First post-treatment scans and surveillance scans detected more recurrences than clinical exams. A high burden of surveillance scans is needed to detect 1 recurrence, especially beyond 2 years from treatment.