Improving Functional Oral Intake in Head and Neck Cancer Survivors with Chronic Radiation-Associated Dysphagia – The Multicenter Randomized Controlled HIT-CRAD Trial

This randomized controlled trial evaluated the efficacy of home-based treatment programs for chronic radiation associated dysphagia (CRAD) in head and neck cancer (HNC) patients, comparing high-volume strength training to combined strength-skill training with either real or sham High-Definition transcranial Direct Current Stimulation (HD-tDCS). 54 HNC survivors with CRAD were randomized in 3 groups, each performing exercises 4 times per week over 8 weeks. Group 1 (n = 18) received strength training only, consisting of tongue strengthening exercises, chin tuck against resistance exercises with effortful swallowing and expiratory muscle strength training. Group 2 (n = 18) completed the same regimen for 4 weeks, followed by 4 weeks of skill training according to the McNeill Dysphagia Therapy Program. Group 3 (n = 18) completed this combined therapy program while receiving HD-tDCS over the swallowing motor cortex during each therapy session. To examine the additional effect of HD-tDCS, group 2 received sham stimulation. All groups showed significant improvements in functional oral intake (p < .001), swallowing function (p < .05) and muscle strength (p < .001). Participants receiving combined strength and skill training (group 2 + 3) had significantly greater odds of better oral intake outcomes after 8 weeks of training (OR 13.47, 95%CI 5.95 - 30.49, p < .001) compared to the strength-only group (group 1) (OR 3.04, 95%CI 1.44 - 6.44, p = .004). There was no additional benefit of HD-tDCS when comparing group 2 and 3. High-volume strength and skill-based training is an effective intervention for CRAD in HNC survivors. Combining strength and skill training is the most efficient choice to improve functional oral intake.