P0226 Patterns of recurrence in locally advanced squamous cell carcinomas of the head and neck after three-dimensional conformal radiotherapy: An institutional experience

Abstract

Background Loco-regional recurrences continue to plague head and neck cancers, even with combined modality treatment. We report patterns of loco-regional recurrence after three-dimensional (3D) conformal radiotherapy among patients with locally advanced (non-nasopharyngeal) head and neck squamous cell cancers. Methods From 2009 to 2012, 263 patients with stage III–IV head and neck squamous cell carcinoma received treatment at our institute with radical external beam radiotherapy with or without chemotherapy. Patients who had surgical resection of primary tumour or nodal site were excluded. Sites of loco-regional relapses were compared and correlated with radiotherapy treatment plans by the radiation oncologist and medical physics team. Findings Median follow-up was 38 months (range 3–62). Median patient age was 52 years. After a mean follow-up of 21 months (range 0–44), there were 42 patients with loco-regional failure. The median time to failure among these patients was 12.5 months (range 3–17). Of the 42 cases, 20 failed locally, 17 had regional failure, and five had simultaneous loco-regional failure. 38 patients had in-field recurrence, three had simultaneous in-field and out-of-field recurrence, and one patient had marginal recurrence. Interpretation In this study, the predominant pattern of recurrence after 3D conformal radiotherapy was in-field. Sites of primary gross disease and nodal levels initially involved were the most common sites of recurrence. Further studies on radio-resistant tumour populations are needed, to enhance early identification and appropriate treatment intensification.