RESUMEN

Objective To study the early response and acute/subacute adverse effects after particle radiation therapy for adenoid cystic carcinoma (ACC) of the head and neck.Methods Between May 2015 and March 2016,a total of 8 patients with ACC of the head and neck were treated using proton and/or carbon-ion radiation therapy.Three patients had early stage and 5 had locally advanced disease.Five patients had an R2 and three achieved an R1 resection.Results Seven patients received intensitymodulated proton therapy (IMPT) followed by intensity-modulated carbon-ion therapy (IMCT) boost.One patient received IMPT only.Among the five patients who had an R2 resection,2/3 patients had partial response (PR)/stable disease (SD) at the end of radiation,0/3 achieved PR/complete response (CR) at 1-month follow-up,and 1/2 achieved PR/CR at 3-months' follow-up after the completion of radiation,respectively.Two patients experienced Grade Ⅲ mucositis during radiation therapy.No patient experienced moderate or severe skin reactions.At the time of this analysis,all patients are alive and no patient had disease progression or recurrence.Conclusions The short-term outcomes indicated that particle therapy is safe and potentially efficacious in the management of head and neck ACC.However,longer follow up is needed to assess late toxicities and long-term efficacy.