Change of skeletal muscle mass and associated factors during radiotherapy and chemoradiotherapy in patients with head and neck squamous cell carcinoma

Background and purpose: The aim is to investigate whether lumbar skeletal muscle index (LSMI) decreases during treatment of head and neck squamous cell carcinoma (HNSCC) patients, and which pre-treatment variables are associated with change. Materials and methods: The LSMI before and during treatment was assessed using MRI scans of HNSCC patients treated with radiotherapy (RT) or chemoradiotherapy (CRT). Mixed models assessed LSMI change and pre-treatment covariates (i.e. age, BMI, tumor characteristics and treatment type). Results: In 63 patients the LSMI decreased from 40.56 cm²/m² to 39.96 cm²/m² (p trend = 0.008) on average. The LSMI of CRT patients decreased more than the LSMI of RT patients, but this was not significant (40.85–39.63 cm²/m² vs. 40.37 to 40.19 cm²/m²; p-interaction = 0.052). No effects of pre-treatment covariates on the LSMI trend over time were observed. Conclusion: LSMI decreased during treatment in HNSCC patients, which was not related to pre-treatment variables, but seemed slightly larger for CRT patients than RT patients.