ABSTRACT
PURPOSE: To describe the utilization pattern of head and neck (HN) surveillance imaging and explore the optimal strategy for radiologic "residual" lymph node (LN) surveillance following definitive (chemo)radiotherapy (RT/CRT) in human papillomavirus (HPV)+ oropharyngeal carcinoma (OPC). METHODS: All HPV+ OPC patients who completed RT/CRT from 2012 to 2015 were included. Schedule and rationale for post-treatment HN-CT/MRI were recorded. Imaging findings and oncologic outcomes were evaluated. RESULTS: A total of 1036 scans in 412 patients were reviewed: 414 scans for first post-treatment response assessment and 622 scans for the following reasons: follow-up of radiologic "residual" LN(s) (293 scans/175 patients); local symptoms (227/146); other (17/16); unknown (85/66). Rate of scans with "unstated" reason varied significantly among clinicians (3-28%, p < 0.001) and none of them yielded any positive imaging findings. First post-treatment scans identified 192 (47%) patients with radiologic "residual" LNs. Neck dissection (ND) was performed in 28 patients: 16 immediately (6/16 positive), 10 after one follow-up scan (2/10 positive), and 2 after 2nd follow-up scan (1/2 positive). Thirty patients had >2 consecutive follow-up scans at 2-3-month intervals, and none showed subsequent imaging progression or regional failure. CONCLUSIONS: Pattern of HN imaging utilization for surveillance varied significantly among clinicians. Imaging surveillance reduces the need for ND. However, routine HN-CT/MR surveillance without clinical symptoms/signs does not demonstrate proven value in identifying locoregional failure or toxicity. Radiologic "residual" LNs without adverse features are common. If two subsequent follow-up scans demonstrate stable/regressing radiologic "residual" LNs, clinical surveillance without further imaging appears to be safe in this population.
