This Phase 1 dose-finding study investigates the maximal tolerated dose for a subsequent phase 2 trial testing MR-guided individualized response-adaptive dose prescription in HNC.

This single-center, non-randomized interventional dose-finding phase I trial evaluates the maximal tolerated boost dose with respect to dose limiting toxicities in patients with locally advanced head and neck squamous cell carcinoma (UICC stage III/IVB) with an indication for a primary radiochemotherapy. The primary aim of the trial is to define the maximal tolerated dose in an ADC-based subvolume using an adaptive SBRT-boost areal. Dose-escalated SBRT boost to ADC-high risk volume will be delivered once a week and is defined according to the the actual imaging immediately performed prior to delivery (real-time adaptive) i.e. it can vary from one week to another and it might also be reduced throughout the course of treatment (response adaptive). In case of complete disappearance of high-risk subvolumes sufficient large enough to boost (<5ml), no further ADC boost but only the floor-boost dose is given. The dose escalation of the ADC-high risk volume boost is graduated in four dose levels of 5x5 Gy, 5x5.5 Gy, 5x6 Gy, 5x6.5 Gy in a classical 3+3 dose-finding design where 3 patients per radiation dose level are enrolled. Primary endpoint is the dose limiting toxicity, any acute and late non-hematologic grade 4 or 5 related to the radiotherapy intervention, ≥ grade 3 CTC v.5. oral mucositis at 3 months after radiotherapy.

Inclusion Criteria:

• Age: older than 18 years
• WHO (ECOG) performance status 0-2
• Histological proven HNC (squamous cell carcinoma)
• HPV negative tumors or high risk HPV positive tumors
• Stage III - IVB HNC of the hypopharynx, oropharynx and oral cavity according to UICC and AJCC guidelines
• Tumor extension and localization suitable for radiochemotherapy with curative intent
• Simultaneous standard chemotherapy with cisplatin applicable (no contra-indications)
• Dental examination and -treatment before start of therapy
• For women with childbearing potential and men in reproductive ages adequate contraception.
• Ability of subject to understand character and individual consequences of the clinical trial
• Written informed consent (must be available before enrolment in the trial)

Exclusion Criteria:

• Refusal of the patients to take part in the trial
• Presence of distant metastases (UICC stage IVC)
• HPV positive tumors UICC Stage III with T1/2 N3, despite of smoking status
• Previous radiotherapy in the head and neck region
• Second malignancy that is likely to require treatment during the trial intervention or follow-up period or that, in the opinion of the physician, has a considerable risk of recurrence or metastases within the follow-up period
• Serious disease or medical condition with life expectancy of less than one year
• Participation in competing interventional trial on cancer treatment
• Patients who are not suitable for radiochemotherapy
• Pregnant or lactating women
• Patients not able to understand the character and individual consequences of the trial
• Nasopharyngeal and glottis laryngeal carcinomas
• Patients with contraindications for magnet-resonance tomography