Evaluation of weight loss during intensity-modulated radiation therapy for head and neck cancer patients

The purpose of this study was to investigate the predictive factors of weight loss in head and neck cancer patients treated by intensity-modulated radiation therapy（IMRT）. We retrospectively reviewed 43 patients with head and neck cancers treated with radical RT at doses ≥ 60Gy from January 2016 to December 2018. All patients received chemo-IMRT. The median weight loss was 8.5％. The incidence of weight loss ≥ 5％ was 88％ （38 patients）and ≥ 10％ was 35％（15 patients）. The factors significantly associated with ≥ 10％weight loss in the univariate analysis were younger age（p＝0.009）, size of planning target volume for gross tumor volume （＜0.001）, size of total planning target volume including prophylactic nodal areas（p＝0.021）, presence of lymph node metastasis（p＝0.04）, higher maximum radiation dose in the oral cavity（p＝0.02）, and dental status（max-illary and/or mandibular edentulous, p＝0.008）. Sex, body mass index, tumor site, T stage, diabetes mellitus, percutaneous endoscopic gastrostomy, and mean dose of radiation in the oral cavity were not significantly associated with weight loss. In multivariate analysis of ≥ 10％ weight loss, younger age（p＝0.03）and dental status （dentulous patient, p＝0.013）were significantly associated with weight loss. From these results, younger age and dental status（dentulous patient）might be predictors of ≥ 10％ weight loss during IMRT for head and neck cancer.