Definitive Chemo-Radiotherapy for Regionally Advanced Head and Neck Cancer With or Without Up-front Neck Dissection

70 Gy in 35 fractions to the macroscopic disease 50 Gy in 25 fractions (if sequential boost) or 56 Gy in 35 fractions (if simultaneous integrated boost) to the elective volumes 66 Gy in 35 fractions to the post-operative region with lymphatic extracapsular extension (Arm B only)

"100 mg/m2 every three weeks during radiotherapy~In Arm B, chemotherapy can be omitted in case of a cT1-2 primary and a surgical downstaged pN0-1 neck without lymphatic extracapsular extension."

"Early salvage neck dissection in case of residual lymph node disease will be performed based on the response evaluation by MRI and PET/CT performed 3 and 4 months after the end of (chemo)radiotherapy, respectively (and additional diagnostic modalities if clinically indicated by the physician) and not more than 3 weeks after this post-radiotherapy evaluation.~In Arm A, a successful early salvage neck dissection without the operation of the primary tumor in case of less than clinical complete response (cCR) will be considered a component of the multimodality treatment and not as a failure."