ESTRO 2024 - Abstract Book

S1226

Clinical - Head & neck

ESTRO 2024

1 Seoul National University Hospital, Radiation Oncology, Seoul, Korea, Republic of. 2 Seoul National University College of Medicine, Radiation Oncology, Seoul, Korea, Republic of. 3 Seoul National University Bundang Hospital, Radiation Oncology, Gyeonggi-do, Korea, Republic of

Purpose/Objective:

Though radiation therapy (RT) or concurrent chemoradiation therapy (CCRT) is a key modality in the treatment of head and neck cancer (HNC), most patients experience mucositis, nausea, loss of appetite, and consequent weight loss. These problems often cause sarcopenia, which has a negative impact on treatment compliance and overall survival. We assessed the body composition of HNC patients using automatic volumetric segmentation and investigated the clinical impact of sarcopenia.

Material/Methods:

A total of 227 patients who underwent RT or CCRT for HNC between 2006 and 2021 were recruited for the multi institution cohort. CT images were taken within 3 months before treatment, and within 6 months after the completion of treatment. Body composition was analyzed using Deep Catch v1.1.8., which is a deep neural network model for the automatic volumetric segmentation of body composition. We assessed muscle mass based on the auto-segmented whole-body skeletal muscle index (WB-SMI), which is the volume (cm3) of skeletal muscle between the vertex and the lower margin of the ischial tuberosity, divided by the craniocaudal length of the scan field (cm), and then divided by the height squared (m2). The data of complete blood cell count, albumin, and uric acid level was also collected. Overall survival (OS) was calculated from the last date of the treatment. Patients who experienced disease progression prior to the follow-up CT were excluded.

Results:

In this cohort, with a median follow-up of 63.3 months, the 5-year OS rate was 80.5%. There was a significant reduction in the WB-SMI after treatment (mean difference, 5.12 cm²/m², 95% confidence interval [CI] 4.38 – 5.85, p <0.001). In the multivariate analysis, age ≥ 65 years (hazard ratio [HR] 2.46, 95% CI 1.42– 4.98, p=0.006), male sex (HR 8.28, 95% CI 2.20 –25.22, p =0.001), baseline albumin levels ≤ 3.5 g/dL (HR 4.24, 95% CI 1.96– 10.18, p <0.001), post treatment WB-SMI (HR 0.93, 95% CI 0.88 – 0.99, p =0.030), and hyopharyngeal cancer (HR 2.70, 95% CI 1.10 – 6.54) were found to have a significant association with OS. With maximally selected rank statistics, the optimal cut-off of WB-SMI for OS was 55.2 cm²/m² for males and 44.7 cm²/m² for females. According to this new cut-off, 64 (28.2%) patients had sarcopenia before treatment, while 129 (56.8%) patients developed sarcopenia after treatment. Additionally, there was a significant difference in 5-year OS between patients who maintained muscle mass during treatment, who developed sarcopenia during treatment, and who had sarcopenia from the beginning of the treatment. (90.8% Vs. 80.1% Vs. 63.2%, p =0.043, 0.004, respectively).