PH-0049 Reduction of GTV to CTV radiation margin in head and neck squamous cell carcinoma is oncological safe and significantly reduced acute and late radiation-related toxicity. (August 2021) - Al-Mamgani, A.; Kessels, R.; Navran, A.; Hamming-Vrieze, O.; Zuur, C.L.; de Boer, J.P.; Jonker, M.C.; Janssen, T.; Sonke, J.; Marijnen, C.A.