Moderate Whole Body Hyperthermia for Patients Undergoing Re-irradiation for Head and Neck Cancer -Influence on the Tumor Microenvironment

The aim of the study is to determine the feasibility and efficacy of moderate weekly whole Body hyperthermia Treatment during radiochemotherapy for pre-irradiated locally or regionally recurrent head and neck squamous cell carcinomas. The Primary aim of the study is feasibility, defined as 80% of patients completing at least four applications of hyperthermia. Secondary endpoints include an increase of Tumor Perfusion by the use of hyperthermia, measured by magnetic resonance Imaging during week two of Treatment and reduction of Tumor hypoxia, measured by hypoxia specific Positron emission tomography.