Photon Therapy Versus Proton Therapy in Early Tonsil Cancer.

Inclusion criteria

• The patient must be at least 18 years old.
• Histologically or cytologically confirmed, previously untreated squamous cell carcinoma of the tonsil T1-2 (p16-positive or p16-negative) N0-1 M0 (p16-positive)/N0-N2b M0 (p16-negative) according to AJCC 8th edition, aimed for unimodal and ipsilateral treatment with radiotherapy with curative intent. The treatment may be followed but not preceded by surgery, which would be as a salvage procedure and not part of the planned treatment. An excision of a lymph node, or a tonsillectomy for diagnostic purposes does not exclude the patient from participation.
• World Health Organisation/Eastern Cooperative Oncology Group (WHO/ECOG) performance status 0-1.
• The patient must be able to understand the information about the treatment and give a written informed consent.

Exclusion criteria

• Patients judged to benefit from bilateral radiotherapy or concomitant chemotherapy
• Concomitant or previous malignancies. Exceptions are adequately treated basal cell carcinoma or squamous cell carcinoma of the skin, or in situ carcinoma of the cervix uteri with a follow-up time of at least 3 years, or other previous malignancy with a disease-free interval of at least 5 years.
• Two or more synchronous primary cancers in the head and neck region at time of diagnosis
• Previous surgery or radiotherapy in the head and neck region that may affect the study result, as judged by the investigator
• Co-existing disease prejudicing survival (expected survival should be >2 years).
• Psychiatric or addictive disorders or other medical conditions which in the view of the investigator might impair patient compliance
• When dental fillings with amalgam or metal are present close to the tumour area it must be considered if this may affect radiotherapy before inclusion.