Inclusion Criteria:  Histologically confirmed local recurrence of breast cancer after close resection (≤1mm Resection margin), R1 or R2 resection respectively inoperable recurrence of the chest wall age ≥18 Jahre ECOG PS 0-2 Estimated life expectancy more than 2 years Informed consent  Exclusion Criteria:  Extensive distant metastases that have an estimated life expectancy of <2a Heart disease: severe heart failure (NHYA III / IV), coronary heart disease, state after Myocardial infarction within the last 6 months), AV block III ° Cardiac pacemaker Second malignancy (except cervical carcinomas in situ, local controlled basaliomas, superficial bladder carcinomas (Ta, Tis, T1) or other carcinomas that have lasted more than 5 years behind and have been treated curatively) Pregnancy or breastfeeding Implanted port on the side to be treated in the Hyperthermia field (located contralateral is not an exclusion criteria) Subclavian vein thrombosis less than <6 months behind Other circumstances that preclude hyperthermia Circumstances that conflict with regular follow-up care Transplanted organs Other implants of the ipsilateral chest wall