Personal Health Train for Radiation Oncology in India and The Netherlands

Inclusion Criteria: * Histologically confirmed diagnosis of head and neck squamous cell carcinoma (HNSCC) * Head and Neck primary tumor site: oral cavity, oropharynx, larynx or hypopharynx * Treated between 01-2008 and 12-2017 * Clinical stage III and IV (a, b) according to TNM 7th edition * No distant metastases (M0) * Treated with curative intent: primary definitive radiation therapy with or without systemic treatment * Availability of baseline imaging: * Planning CT scan of the HN region in treatment position, with RT-structures available, performed with contiguous cuts of 2-3 mm or less in slice thickness with i.v. contrast * (if available) FDG-PET in treatment position Exclusion Criteria: * Any previous HNC * Patients with previous malignancies in the last 5 years before treatment for HNC, with the exception of surgically cured carcinoma in situ of the cervix, in situ breast cancer, incidental finding of stage T1a or T1b prostate cancer, and basal/squamous cell carcinoma of the skin * Any previous malignancy that was treated with surgery and/or radiation of the head and neck region * Histological type other than HNSCC * Cancers originating in the oral cavity, nasopharynx, salivary glands or sinonasal area * Postoperative radiation treatment setting