Rare entities in head-and-neck cancer: salvage re-irradiation with carbon ions

Background The objective of this investigation is to evaluate the outcomes and toxicity of carbon-ion re-irradiation (CIR) in patients with rare head and neck cancers (HNC). There is a paucity of data regarding treatment approaches in this patient cohort, which we aim to address in this work. Methods Thirty-two (n = 32) consecutive patients with uncommon HNC treated between 2010 and 2017 were retrospectively analyzed in terms of clinical outcomes, patterns of failure, and toxicity. Results Mucoepidermoid carcinoma (MEC) was the most common histology (22%). Patients received a median cumulative dose equivalent in 2 Gy fractions (EQD2) after CIR of 128.6 Gy (range, 105.8–146.5 Gy). The local and distant control rates 1 year after CIR were 66 and 72%. No serious acute or late toxicity (≥ grade 3) after CIR was observed. Conclusions CIR may represent an effective and safe treatment alternative to palliative systemic therapies in these rare indications.