[Induction of solid tumors by ionizing radiation].

Secondary malignancies are a rare complication after irradiation. 31 observations of such tumours are described, which appeared 4 to 56 years after radiotherapy. The NSD values varied between 400 and 3500 ret. 19 patients developed sarcomas and 12 others carcinomas. The hypotheses of radiation induced tumours and their clinical relevance are discussed. Three patient groups at risk may be distinguished: 1. children, 2. patients who received several treatment series, 3. patients who received combined radio- and chemotherapy.