151751-Najiba-Chargi

198 CHAPTER 11 ABSTRACT Objectives Low skeletal muscle mass (SMM) is an adverse predictive factor for chemotherapy dose-limit - ing toxicity (CDLT) in cancer patients. In patients with locally-advanced-head-and-neck-squa - mous-cell-carcinoma (LA-HNSCC) undergoing primary chemoradiotherapy (CRT), low SMM is a predictor for CDLT. We aimed to validate these findings. Materials and methods Consecutive LA-HNSCC patients treated with primary CRT with high-dose cisplatin were retro - spectively included. SMMwas measured on pre-treatment CT-imaging. A cumulative cisplatin dose below 200mg/m 2 was defined as CDLT. Results 153 patients were included; 37 (24.2%) experienced CDLT and 84 had low SMM (54.9%). Pa - tients with low SMM experienced more CDLT than patients with normal SMM (35.7% vs 10.1%, p<0.01). Low SMM (OR 3.99 [95%CI 1.56–10.23], p=0.01) and an eGFR of 60-70 mL/min (OR 5.40 [95%CI 1.57–18.65], p<0.01) were predictors for CDLT. Conclusion Pre-treatment low SMM is associated with CDLT in LA-HNSCC patients treated with primary CRT. Routine SMM assessment may allow for CDLT risk assessment and treatment optimal - ization.