Abstract Background Chronic radiation-associated dysphagia (C-RAD) is considered to be one of the most severe functional impairments in head and neck cancer survivors treated with radiation (RT) or chemoradiation (CRT). Given the major impact of these late toxicities on patients’ health and quality of life, there is a strong need for evidence-based dysphagia management. Although studies report the benefit of strengthening exercises, transference of changes in muscle strength to changes in swallowing function often remains limited. Therefore, combining isolated strengthening exercises with functional training in patients with C-RAD may lead to greater functional gains. Methods This 3-arm multicenter randomized trial aims to compare the efficacy and possible detraining effects of mere strengthening exercises (group 1) with a combination of strengthening exercises and functional swallowing therapy (group 2) and non-invasive brain stimulation added to that combination (group 3) in 105 patients with C-RAD. Patients will be evaluated before and during therapy and 4 weeks after the last therapy session by means of swallowing-related and strength measures and quality of life questionnaires. Discussion Overall, this innovative RCT is expected to provide new insights into the rehabilitation of C-RAD to optimize post-treatment swallowing function. Trial registration International Standard Randomized Controlled Trials Number (ISRCTN) registry ID ISRCTN57028065. Registration was accepted on 15 July 2021.
