Gu F, Farrugia MK, Duncan WD, et al. - Using electronic medical records, researchers examined head and neck squamous cell carcinoma patients (n = 190), to assess the link between daily delivery time of radiotherapy and the severity of oral mucositis (a common, debilitating complication of cancer treatment) in these patients. The participants had completed radiotherapy, with or without concurrent chemotherapy, and were recruited from Roswell Park Comprehensive Cancer Center. Weekly, a validated oral mucositis questionnaire was applied to obtain self-reported patient mouth and throat soreness (MTS), with responses 0 (no)~4 (extreme), throughout a seven-week therapy course. A significant link of radiation treatment time with the oral mucositis severity was observed, employing both repeated-MTS and maximum-MTS, with consistent patterns. For patients treated during 8:30-<9:30am, the lowest severity was reported, and severity raised at later treatment times and peaked at early afternoon, and then declined substantially following 3 pm. Overall, in head-neck cancer patients, findings revealed a significant link between radiation therapy time and oral mucositis severity.