MULTIPLE COURSES OF HIGH-DOSE TOTAL SKIN ELECTRON-BEAM THERAPY IN THE MANAGEMENT OF MYCOSIS-FUNGOIDES

Purpose: A retrospective analysis was undertaken to determine the indications for, the efficacy of, and the long-term complications of two courses of total skin electron beam therapy for mycosis fungoides. Methods and Materials: A retrospective analysis of 15 patients with the pathologic diagnosis of mycosis fungoides treated in the Department of Radiation Oncology at Stanford University Medical Center between 1968 and 1990 was performed. All patients received two courses of high-dose electron beam therapy to the skin. The mean dose for the total skin treatment for the first course was 32.6 Gy and 23.4 Gy for the second course of treatment. Results: Following the first course of total skin electron beam therapy, 11 of 15 had a complete response, with a mean duration of 11.6 months. All patients received adjuvant therapies between the first and second courses of high-dose total skin electron beam therapy. The mean interval between the first and the second courses of therapy was 41.3 months. Patients were restaged prior to commencement of their second course of high-dose total skin electron beam therapy, resulting in upstaging in six. The second course of therapy resulted in six complete responses and nine partial responses. Twelve of these patients have since died, 1 is lost to follow-up, and 2 are living with disease. The long-term side effects in the two living patients include pigmentation changes, alopecia, and diffuse xerosis. Conclusion: Delivery of two courses of total skin electron beam therapy is technically feasible, tolerable, and efficacious. The dose to the total skin was reduced for the second course of therapy in all cases. The criteria used to screen patients included initial good response to total skin electron treatment, long disease-free interval, exhaustion of other therapeutic modalities, and generalized skin involvement at relapse. Longterm toxicities were mild in severity and generally consisted of generalized xerosis, scattered telangiectasias, pigmentation changes, and partial alopecia.