Patterns of Failure in Patients Treated With Intensity Modulated Radiation Therapy (IMRT) Using Helical Tomotherapy (HT) for Head-and-Neck Squamous Cell Carcinoma (HNSCC): Results of a Prospective Trial

Abstract

mass index (BMI) is associated with improved recovery from CRT and survival. Emerging evidence suggests that BMI may be used in conjunction with other body composition indices, including skeletal muscle and visceral adipose loss to individualize nutritional assessment and survival prognostication. This study evaluates the effect of body composition changes on survival in a population-based cohort of patients with locally advanced HNC treated with curative intent. Materials/Methods: A retrospective review was performed on 43 patients with Stage III/IV HNC treated with radical RT chemotherapy between 2007 and 2010. Preand post-treatment CT datasets encompassing the L3 vertebral body were available in 36 cases. Visceral adipose tissue and skeletal muscle cross sectional area (cm) were contoured at the L3 level with Eclipse v.10.0, using established thresholds of Hounsfield units. Pre and post treatment weight and BMI were recorded. Body composition indices analyzed included pre-treatment BMI, changes in skeletal muscle and visceral adipose tissue. Results: Median follow-up was 23.1 months. Mean disease specific survival (DSS) was 37.6 months. The average weight loss on treatment was 5.1kg. 72% of patients had acute grade 2 dysphagia and 79% had grade 2 mucositis. The median time from end of treatment to repeat CT scan was 3.1 months. Of 36 cases with preand postCT scans, the mean skeletal muscle loss was 19.5 cm and mean visceral adipose loss was 54.0 cm. Mean DSS was 38.3 months (95% CI 32.8-43.9) in patients with pretreatment BMI 25 kg/m vs. 30.2 months (95% CI 23.4-37.0) with BMI <25 kg/m (P Z NS). Mean DSS was longer in patients with post-treatment skeletal muscle loss <20 cm and visceral adipose loss <50%, but the differences were not statistically significant (Table). Conclusion: The observation of a trend toward improved survival in HNC patients with high pre-treatment BMI is consistent with other reports. Though not statistically significant, a trend toward longer survival was also observed with lower post-treatment skeletal muscle and visceral adipose loss. These preliminary findings support the plan to expand the cohort to increase sample size, calculate lean body mass based on established regression models, and correlate body composition changes with survival.