Impact of sarcopenia on acute radiation-induced toxicity in head and neck cancer patients

•Sarcopenic patients experience more frequent toxicities prior to radiotherapy.•Sarcopenia is an independent adverse prognostic factor for RT-induced dysphagia.•Besides dysphagia, sarcopenia is not associated with acute RT-induced toxicities.•Sarcopenia does not improve the current NTCP models for acute toxicities. Sarcopenia is related to late radiation-induced toxicities and worse survival in head and neck cancer (HNC) patients. This study tested the hypothesis that sarcopenia improves the performance of current normal tissue complication probability (NTCP) models of radiation-induced acute toxicity in HNC patients. This was a retrospective analysis in a prospective cohort of HNC patients treated from January 2007 to December 2018 with (chemo)radiotherapy. Planning CT scans were used for evaluating skeletal muscle mass. Characteristics of sarcopenic and non-sarcopenic patients were compared. The impact of sarcopenia was analysed by adding sarcopenia to the linear predictors of current NTCP models predicting physician- and patient-rated acute toxicities. The cut-off values of sarcopenia in the study population (n = 977) were established at skeletal muscle index