The rate of therapy-associated side effects during and after radiotherapy of head and neck tumors is essential. The most effective approach to reducing acute toxicity is to cut out healthy tissue from the radiation field. The distance between the tumor and normal tissue can be individually increased using personalized, 3D printer-based tissue retractors (GWR). Even the smallest geometric changes lead to a significant dose reduction in normal tissue and significant advantages for the patient.

The current randomized phase II study evaluates the use of GWR with regard to acute toxicity. In addition, quality of life, long-term toxicity as well as local control and overall survival 12 months after radiotherapy are evaluated.

The most effective approach to reducing acute toxicity after radiotherapy is to cut out healthy tissue from the radiation field. GWR can increase the distance between the tumor and normal tissue. Even the smallest geometric changes lead to a significant dose reduction in normal tissue and significant advantages for the patient. Adequate immobilization also reduces unwanted movements, especially of the tongue.

The GWR are manufactured as combinable modules according to the "modular principle". This improves reproducibility and flexibility and reduces development and manufacturing costs. The study is being conducted as a monocentric, prospective, randomized phase II study. A total of 34 patients who meet the inclusion criteria are examined for acute toxicity after radiotherapy of a malignant head and neck tumor. The primary goal of the study is to reduce acute toxicity through individual immobilization of the jaw and tongue. Secondary study goals are the evaluation of quality of life and long-term toxicity as well as local control and overall survival twelve months after radiotherapy. In both groups, radiation therapy is carried out in accordance with guidelines using image-guided radiotherapy.

Inclusion Criteria:

• Diagnosis of a malignant head and neck tumor
• Clinical target volume of radiotherapy may include portions of at least one region: oral cavity; Upper jaw; Lower jaw; Oropharynx; Hypopharynx; large salivary glands
• Indication for radiotherapy alone (postoperative or definitive)
• Age ≥ 18 years
• Karnofsky performance score ≥ 60
• Completed wound healing after tumor resection
• The patient's consent and written consent
• Ability of the patient to assess the nature and scope as well as possible consequences of the clinical study
• Adequate contraception in women of childbearing potential and in men

Exclusion Criteria:

• Pre-radiation in the head and neck area
• Multifocal, diffuse growing tumors
• Inadequate regression of toxicities from previous therapies
• Jaw clamp (cutting edge distance ≤ 2 cm)
• Simultaneous systemic tumor therapy during radiation (especially chemotherapy and immunotherapy)
• Indications that the participant is unlikely to adhere to the study protocol (e.g. lack of compliance)
• Missing written declaration of consent