Full-dose re-irradiation using helical tomotherapy as a treatment for recurrent and second primary head-and-neck cancer

Abstract

Purpose: Limited information regarding re-irradiation (re-RT) for recurrent and second primary head and neck cancer are available until now. Here we studied our initial experience of helical tomotherapy for previously irradiated head and neck cancer. Patients and Methods: Retrospective review was performed for 36 consecutive patients re-irradiated with helical tomotherapy for head and neck cancer between 2006 and 2012. The re-RT targets encompassed only the recurrent gross tumor with tight margins (5-10 mm).Results: Twenty-three (64%) patients underwent salvage surgery before re-RT and 26 (72%) patients received concurrent chemotherapy during re-RT. The median time interval between initial RT and re-RT was 34 months and the median cumulative dose of the two irradiations was 125 Gy. The median overall survival was 17 months. Fourteen patients (39%) developed loco-regional recurrences after re-RT (8 in-field, 6 out-field). In multivariate analysis, the higher cumulative RT dose, the longer time interval, and the use of concurrent chemotherapy were associated with improved loco-regional recurrence-free survival (all p < 0.05). Additionally, the longer time interval, the smaller gross tumor volume, and the male sex were associated with better overall survival. Ten patients (39%) showed clinically significant late toxicity among 26 evaluable patients but no grade 5 toxicity was observed.Conclusion: We report moderate safety and acceptable acute and late toxicity after helical tomotherapy re-RT using tight margin and daily image-guidance. The current data showed encouraging local control and survival which is similar with the historical data using 1-2 cm margins.