The role of radiation therapy in the management of dermatofibrosarcoma protuberans

Purpose: To evaluate the outcome for dermatofibrosarcoma protuberans treated with conservation surgery and radiation therapy. Methods and Materials: A retrospective review was performed of 19 consecutive patients with pathologically confirmed dermatofibrosarcoma protuberans who received radiation as an adjuvant to surgical resection. Results: The patients ages ranged from 19-76 years (median, 40 years); 12 were men. Lesions were located on the trunk in 8, in the head and neck area in 7, and in an extremity in 4. Tumor size ranged from 1.2 to 15 cm (median, 4 cm). Ten patients had at least 1 prior recurrence following earlier resection. Two patients received preoperative radiation to 50 Gy in 5 weeks. Sixteen patients underwent resection followed by radiation (6 of these had positive resection margins). In another patient, the tumor regrew rapidly after resection and definitive radiation was delivered foe gross disease. The 6 patients with positive microscopic margins received a median dose of 60 Gy, as did the 10 with negative margins. The 1 patient with gross disease received 65 Gy. At a median follow-up of 6 years, the only patient to develop local recurrence was treated with definitive radiotherapy for gross disease. Actuarial local control was 95% at 10 years. Conclusion: Dermatofibrosarcoma protuberans is a radioresponsive tumor and radiation to doses of 50-60 Gy should be considered as an adjuvant to resection if margins are positive. Combined conservation resection and postoperative radiation should also be considered for situations where adequate wide excision alone would result in major cosmetic or functional deficits.