Optimising (Re-)Irradiation for Locally Recurrent Head and Neck Cancer: Impact of Dose-Escalation, Salvage Surgery, PEG Tube Dependence and Biomarkers on Oncological Outcomes

Abstract Introduction: Locoregional recurrence (LR) is common in locally-advanced head and neck cancer (HNSCC), posing challenges for treatment. We analysed outcome parameters and toxicities for patients being treated with radiotherapy (RT) for LR-HNSCC and investigated patient and disease related prognostic factors in this prognostically unfavourable group. Methods This analysis includes 101 LR-HNSCC patients treated with RT, radio-chemotherapy (RCT) or radio-immunotherapy (RIT) between 2010–2018. Patient characteristics, tumour and treatment details were retrospectively collected. Overall survival (OS), progression-free survival (PFS) and toxicities were assessed. Results 62% of patients were radiotherapy-naïve (initial RT) while 38% were re-irradiated at site of LR (re-RT). Median OS for initial RT was 17 months, for re-RT 9 months (p = 0.005). In the RCT subgroup, patients with initial RT had significantly longer OS with 27 months compared to re-RT 12 months (p = 0.006). Patients requiring a percutaneous feeding tube had significantly shorter OS (12 vs. 27 months) in multivariate analysis. Significant factors for longer OS in univariate analysis included salvage surgery, haemoglobin levels ≥ 12g/dl, low inflammatory status (Glasgow Prognostic Score 0), radiation doses ≥ 50 Gy. We detected 37 (15%) ≥ Grade III events for initial RT and 19 (15%) for re-RT patients. Conclusion We identified key prognostic factors including feeding tube dependence, anaemia, and inflammation status that could guide treatment decision. Our findings suggest salvage surgery as preferred treatment option with postoperative RT in high risk situations. A radiation dose of ≥ 50 Gy should be administered to achieve better outcomes. Adverse events due to re-RT are acceptable using an OAR-driven approach.