Longitudinal Evaluation of Sternocleidomastoid Muscle Stiffness and Self-Reported Fibrosis-Related Symptoms After Radiotherapy in Patients with Head and Neck Cancer. - Verbeelen, Kaat; De Groef, An; Van Aperen, Kaat; Gursen, Ceren; Nuyts, Sandra; Devoogdt, Nele; Mertens, Michel G. C. A. M. (Cancers, 2026)