Patients with primary head and neck squamous cell carcinoma (HNSCC) planned for treatment with radiotherapy with or without chemotherapy in curative setting will be treated with an adaptive radiotherapy scheme. An FDG-PET/CT scan for re-delineation and re-planning will be made at the end of the second and fourth of week of radiotherapy. The non-responding part of the tumor on FDG-PET will receive a mild dose-escalation. Depending on the metabolic response, the entire tumor will receive 70 Gy or the residual FDG-avid area will receive 74 or 78 Gy.

If there is a complete metabolic response on the FDG-PET after 2 weeks, the entire tumor will receive 70 Gy. If there is a complete metabolic response after 4 weeks of treatment, the residual FDG-avid area will receive 74 Gy. If there also is no complete metabolic response after 4 weeks of treatment, the residual FDG-avid area will receive 78 Gy.

Inclusion Criteria:

• Histologic biopsy confirmed squamous cell carcinoma of the oral cavity, HPV-negative oropharynx, HPV-positive oropharynx with a minimum of 10 pack-years, hypopharynx or larynx
• T2-T4
• Scheduled for radiotherapy or radiotherapy with cisplatin or cetuximab

Exclusion Criteria:

• GFR<30
• Other neoplasms with metastases in the previous 3 years