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 (EQD(2)) 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.