The goal of this observational study is to evaluate the toxicity and local tumor control of proton therapy for patients with head and neck cancer in a previously irradiated field.

Standard of care for recurrent or secondary malignancies in a previously irradiated field is surgery. For inoperable patients or residual tumor after surgery, standard of care would be palliative chemotherapy. For a small subset of patients (good performance status, small radiation fields) re-irradiation can be performed. In this study the established concept of re-irradiation with photons will be transferred to proton radiotherapy. Proton therapy has the advantage of a steeper dose gradient to normal tissues, thus-theoretical advantages for lower toxicity.

OBJECTIVES:

Primary: Evaluation of late toxicity of re-irradiation with protons, for patients with head and neck cancer in a previously (> 50 Gy) irradiated field.

Secondary: Evaluation of the efficacy (local control) and acute toxicity (after 24 Months) of re-irradiation with protons up to a dose of 60 Gy, for patients with head and neck cancer in a previously (> 50 Gy) irradiated field.

OUTLINE This is a single center observational study. In-house standard of care for patients (good performance status and with small tumors) with head and neck cancer in a previously (> 50 Gy) irradiated field is to irradiate the tumor with a hyperfractionated schedule and concurrent cisplatin up to a dose of 66 Gy. Dose limiting for this schedule is the incidence of acute and late toxicity induced by radiation. The purpose of the study is the evaluation of the safety of a treatment schedule based on the use of protons.

Proton beam treatments will be delivered in 2 Gy fractions, 5 days per week, to a total dose of 60-66 Gy equivalent.

Study visits are performed:

During proton therapy once per week. Follow-up visits are scheduled every 3 months for the first 24 months after proton therapy.

Primary endpoint is late toxicity 24 months after proton treatment.

Inclusion Criteria:

• tumor is located in a previously irradiated area with at least 50 Gy or there is an overlap of radiation fields with resulting total doses greater than 90 Gy to expect
• tumor size and localization allow high dose re-irradiation (individual decision)
• exclusion of distant metastases
• Time interval between pre-irradiation and re- irradiation at least 1 year for local recurrence; at least 6 months for secondary tumor disease
• age ≥ 18 years
• previous radiotherapy treatment plans available
• pre-treatment imaging (pre re-irradiation) available
• good general condition (ECOG 0-1)
• dental treatment performed, if necessary
• in case of surgery before re-irradiation: resection status is R-1 or R-2
• clinical suspicion of residual tumor by very scarce surgical margins (<1 mm)
• pathological secured extracapsular extension (ECE)
• indications by an interdisciplinary tumor board
• patient able to understand the intention and procedures of the trial, written informed consent

Exclusion Criteria:

• no description of the R- status after resection of the tumour
• pregnancy
• no written informed consent
• distant metastases
• interval between first and second irradiation < 6 months at secondary tumor or <1 year when local recurrence of previously irradiated tumor
• simultaneous participation in another intervention study , if further treatment must be carried out

Patients with a recurrent or secondary head and neck carcinoma