RADIATION IN MANAGEMENT OF PATIENTS WITH DERMATOFIBROSARCOMA PROTUBERANS

Purpose: The preferred treatment of dermatofibrosarcoma protuberans (D FSP) is wide resection, namely, margins greater than or equal to 3 cm beyond the evident disease and histologically negative margins. We ass ess the success achieved by radiation combined with surgery for positi ve/close margins or by radiation alone for those tumors that are not r esectable For technical/medical reasons. The literature on this point is virtually nonexistent. Materials and Methods: The outcome of treatm ent of 18 patients with DFSP by radiation alone (n = 3) and radiation and surgery (n = 15) at the Massachusetts General Hospital was assesse d. All of the lesions at the time of the treatment by radiation alone or combined with surgery were less than 10 cm. This was the maximum di mension. The actual tumor volume was much less than indicated by this maximum dimension, as the tumors were usually relatively flat. Results : The 10-year actuarial local control rate was determined to be 88%. L ocal control was realized in the three patients treated by radiation a lone, with follow-up periods of greater than or equal to 9 years. Amon g 15 patients treated by radiation and surgery, there have been three local failures; the 10-year actuarial local control rate was 84%. The three local failures occurred in 12 patients whose surgical margins we re positive. One of these three local failures developed in the group of two patients whose lesions were scored as grade II. Conclusion: Rad iation in well-tolerated dose schedules is an effective option in the management of patients with DFSP. This appears to be true for radiatio n alone or postoperatively for margin-positive disease (primary or rec urrent). (C) 1996 by American Society of Clinical Oncology.