Severe acute and late dysphagia is now considered as a dose-limiting toxicity of radio(chemo)therapy for head and neck cancer that significantly affects patients' quality of life. We propose to preserve swallowing function by:

• adapting (individualizing) treatment (intensity-modulated radiotherapy: IMRT) to per-treatment changes occurring in the tumor and surrounding organs and tissues;
• reducing the volumes of elective neck, that may result in significant decrease of severe acute and late dysphagia.

Inclusion Criteria:

• Histologically confirmed squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx and larynx.
• Primary non-resected tumor and/or patients refused surgery
• Stage T1-4, N0-3; for cancer of the glottis T3-4 or T any N1-3
• Decision of curative radiotherapy or radiochemotherapy made by a Multidisciplinary Group of Head and Neck Tumors at UZ Gent and UZ Gasthuisberg Leuven
• Karnofsky performance status >= 70 %
• Age >= 18 years old
• Informed consent obtained, signed and dated before specific protocol procedures

Exclusion Criteria:

• Treatment combined with brachytherapy
• Prior irradiation to the head and neck region
• Surgery of the primary tumor except lymph node dissection prior to radiotherapy
• induction chemotherapy
• history of prior malignancies, except for cured non-melanoma skin cancer, curatively treated in-situ carcinoma of the cervix or other cancer curatively treated and with no evidence of disease at least 5 years
• Distant metastases
• Creatinine clearance (Cockroft-Gault) =< 60 milliliter/minute before treatment or creatinine value > 1,3 milligram/deciliter
• Known allergy to the CT-contrast agents
• Pregnant or lactating women
• Mental condition rendering the patient unable to understand the nature, scope and possible consequences of the study
• Patient unlikely to comply with protocol, i.e. uncooperative attitude, inability to return for follow-up visits and unlikely to complete the study