Feasibility and patient reported tolerance of cryotherapy with Cooral mouth cooling device in patients undergoing radiation therapy (CooRay): a pilot study.

Background: Radiation-induced oral mucositis (RIOM) is a major side-effect of (chemo)radiation (CRT) of patients with head and neck cancer (HNC). This study tries to establish a novel cryotherapy (CyT) method using a mouth care device (MCD; Cooral Methods: Patients were non-randomly assigned to use the MCD after every radiotherapy session for 30-60 minutes. Subjects were asked to answer daily questionnaires assessing tolerability of the intervention. Mucositis was assessed at baseline, once weekly and at weeks 1/3/6 after CRT. The primary endpoint was patient tolerance, defined by the time the MCD was used and the patients' perception. Secondary outcomes were the degree (CTCAE v5.0) and duration of RIOM. Results: Ten patients were eligible with a mean age of 62 years. Four patients received concurrent platinum-based CRT, whereas the others received radiotherapy alone. Overall, 214 CyT sessions were performed (73% of planned CyT sessions). The mean daily CyT duration was 48 minutes (range, 30-60 minutes). All patients reported cooling as comfortable. Nine completed the intervention, one terminated it early due to hypersalivation. No Grade 4 RIOM was observed. Grade 3 mucositis was observed in 4 and Grade 2 in 3 cases. Conclusions: The Cooral System was well tolerated, with a duration of application that was acceptable for most patients. We concluded that the MCD can be safely used in patients undergoing CRT. A prospective phase II trial, assessing the efficacy in preventing RIOM, is planned.