ESTRO 2025 - Abstract Book

S941

Clinical – Head & neck

ESTRO 2025

Purpose/Objective: Radical management of head and neck squamous cell cancer (HNSCC) historically includes planned neck dissection after radiotherapy 1 . Surveillance for patients with complete response after radiotherapy for non-bulky nodal disease is also generally accepted 2 but this approach is unvalidated for patients with N3 disease. We report long term outcomes for N3 patients treated with primary neck dissection versus radiotherapy and surveillance. Material/Methods: We retrospectively reviewed consecutive N3 M0 HNSCC patients (TNM7), excluding nasopharyngeal. Patients had either surgical management of the primary and neck dissection followed by post-operative radiotherapy, or primary radiotherapy followed by surveillance in cases of complete response. 66 or 65Gy (primary) or 60Gy (post-operative) in 30 fractions was delivered using intensity-modulated radiotherapy. Concurrent and/or induction chemotherapy was given based on fitness and clinical indications. Patients were imaged 12-16 weeks post-radiotherapy. Patients with resectable residual disease had neck dissection. Patients were followed up three-monthly for two years, four monthly for year three and six-monthly for years four and five. Median time-to-event outcomes and event rates were estimated using the Kaplan-Meier method. Results: Between July 2012 and February 2023, 53 patients with T0-4N3M0 HNSCC were treated radically with primary surgery (n=22) or radiotherapy (n=31). Median (range) follow-up was 25.5 (3-146) months, with opportunity for follow-up of 64 (19-147) months. Figure 1 shows baseline characteristics.