ESTRO 2025 - Abstract Book

S1020

Clinical – Head & neck

ESTRO 2025

Purpose/Objective: For locally advanced head and neck squamous cell carcinoma (HNSCC), poorer outcomes have been associated with prolonged package time (PT) 1 and low haemoglobin 2,3 ; though published results have been inconsistent. We report long term outcomes from our institution. Material/Methods: We retrospectively reviewed consecutive HNSCC patients treated with primary radical surgery and post-operative radiotherapy (PORT). All patients had a high-risk indication for radiotherapy (T3 or T4, multiple nodes or larger than 3 cm, close margins, perineural or lymphovascular invasion, extracapsular spread). Typical dose was 60Gy in 30 fractions delivered using intensity-modulated radiotherapy. Concurrent chemotherapy was given for positive margins or extracapsular spread, if fit and younger than 70. Response was assessed at 12-16 weeks using CT or PET CT. 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. PT was calculated from date of radical surgery to end of PORT, and patients were grouped into those with PT ≤ vs >100 days. Haemoglobin levels during PORT were collected, and patients were grouped into those with minimum haemoglobin ≥ vs <120 g/L. Results: Between April 2012 and November 2023, 170 patients were treated with surgery and PORT. Median (range) follow up duration was 40 (1-146) months, with opportunity for follow-up of 78 (11-149) months. Patient age, gender, N stage and smoking status were balanced between all groups. Patients with PT ≤100 had fewer laryngeal primaries and more T1-2 stages. Patients with haemoglobin ≥120 had more oropharyngeal and fewer laryngeal primaries, more T0-2, less ECS, more p16+ and less concurrent CTX. Median overall survival was 107 months overall, 107 vs 81 for PT ≤100 vs >100 (p=0.564), not reached vs 61 for Hb ≥120 vs <120 (HR 0.44, p = 0.003). Median DFS was 100 months overall, 107 vs 65 for PT ≤100 vs >100 (p=0.928), not reached vs 37 for Hb ≥120 vs <120 (HR 0.33, p<0.001). Estimated two-year and five-year rates of OS, DFS, LRDFS and MDFS were all non-significantly different for PT ≤100 vs >100 (p-values 0.321-1.000) and all significantly different for Hb ≥120 vs <120 (p<0.001).