[Dermatofibrosarcoma protuberans. Results of radiosurgical therapy by photon and electron rays or fast neutrons].

The dermatofibrosarcoma protuberans, a rare entity of soft tissue sarcomas, is specified as a tumor of intermediate malignancy because of its marked tendency to form local recurrences. Regarding the prevention of local recurrences, the results of combined radiosurgical therapy (n = 13) could be improved in our patients by the application of fast neutrons (n = 6). Despite multiple previous operations for recurrences, a reliable prevention of local recurrences (average follow-up period 5.5 years) was achieved in all patients by neutron irradiation with focal doses of approximately 9 Gy. One patient with multiple macroscopic recurrences received two neutron series with 17 Gy. At seven years, she is still recurrence-free. We consider the postoperative irradiation of the dermatofibrosarcoma protuberans with fast neutrons following to primary tumor excision as method of choice for a reliable prophylaxis of local recurrences, because this method allows to dispense with major radical surgery.