[Possibilities and limits of radiotherapy in the treatment of pelvic tumors in childhood].

1. The most frequently occurring malignant tumours of the pelvis in childhood are germ cell tumours, soft-tissue sarcomas and osseous sarcomas. 2. Of the embryonal carcinomas, the dysgerminomas are regularly cured by radiotherapy alone. The other embryonal carcinomas are also radiosensitive. However, in view of the very high success rate of surgery and chemotherapy, radiotherapy is really not necessary. 3. Of the soft-tissue sarcomas, local radiotherapy is necessary only if complete remission of the tumour has not been achieved by surgery and aggressive chemotherapy in the following tumours: embryonal rhabdomyosarcomas, undifferentiated sarcomas and extraosseous Ewing's sarcomas. On the other hand, radiotherapy is necessary for reducing the local relapse rate in the rare types of soft-tissue sarcomas such as alveolar rhabdomyosarcomas and synovial sarcomas. These tumours show a similarly characteristic behaviour as the soft-tissue sarcomas in adults. 4. Of the osseous sarcomas, Ewing's sarcoma of the pelvis always requires aggressive local therapy (surgery and/or irradiation) besides intensive drug therapy.