Total skin electron irradiation for mycosis fungoides: failure analysis and prognostic factors.

From 1970 to 1980, 106 patients with mycosis fungoides received total skin electron irradiation to full tolerance. The majority received 30 Gy of 3 MeV electrons in 12 treatments over three weeks. Eighty-eight patients had received prior therapy. Fifty patients had cutaneous plaques only (T1-2N0), and 56 had more advanced disease. At five years, actuarial survival is 66.7% and disease-free survival 21.4%. The median time to relapse is 12 months; prolonged survival is seen only with complete response. Compared with more advanced stages, T1-2N0 patients have more frequent complete response (96% vs 71%) and better relapse-free survival at five years (32 vs 7%). Of 14 patients with T2 disease in continuous complete remission for from 45-113 months, only one has relapsed. This suggests that cure is possible in up to 26% of patients with T2 disease who achieve complete response. In advanced stages, complete response is more likely with doses over 25 Gy (80 vs 50%). First recurrences were predominently in sites of previous involvement. Death resulted mainly from extracutaneous dissemination or failure to induce remission.