De-escalation of Adjuvant Radio (Chemo) Therapy for HPV-positive Head-neck Squamous Cell Carcinomas

Prior treatment

• R2 resection or macroscopically visible residual tumor after surgery
• interval between last operation and planned irradiation start \> 7 weeks
• contraindication against a guideline-appropriate adjuvant radiation or radiochemotherapy according to the clinical risk constellation
• Pre-irradiation with risk of dose overlap
• participation in another clinical trial if further experimental therapy is necessary or the treatments/ protocols are mutually exclusive (e.g. altered chemotherapy, additional consolidation chemotherapy). Allowed is the additional participation in observation studies or supportive therapy studies.

Other illness

• tumor disease in the last five years before the beginning of the study (except basaliomas of the skin, in-situ carcinoma of the cervix uteri or breast, or tumors with similar prognosis which are considered to be very likely to be cured)
• malignant tumor disease in the head and neck region, regardless of interval and prognosis
• diseases or conditions which do not allow the person concerned to assess the nature and scope and possible consequences of the clinical trial

Other

• Patients with a cumulative nicotine abuse \> 30 packyears. These patients are not included in the intervention arms, but are always included in the observation arms (regardless of HPV status).
• radiologically presumed or histologically confirmed distant metastasis
• no neck dissection
• pregnant or lactating women
• evidence that the participant is not expected to comply with the study protocol (e.g. lack of cooperation)
• missing written consent

• Condition after surgical removal of a squamous cell carcinoma of the oropharynx and adequate lymph node dissection
• Indication for adjuvant radiotherapy or radiochemotherapy in the interdisciplinary tumor board
• Good general state (ECOG performance status 0 or 1)
• Adequate compliance to ensure closely follow-up
• Patient's consent and written consent
• Neck dissection of at least the tumor bearing side
  • Additional Inclusion Criteria Arm intermediate risk (at least one of the criteria must be fulfilled):
• pT3 and R0 and / or
• histologically confirmed involvement of lymph nodes (n = 1-3) and no extracapsular extension of the lymph node metastasis
  • Additional Inclusion Criteria Arm high risk (at least one of the criteria must be fulfilled):
• residual tumor (R1 status) and / or
• pathologic stage T4 (pT4) status and / or
• more than 3 infected lymph nodes and / or
• extracapsular extension of at least one lymph node metastasis