Radiotherapy for Kaposi's sarcoma.

Between 1954 and 1976, 60 patients with Kaposi's sarcoma were treated in the Department of Radiotherapy of the Lahey Clinic Foundation at the High Voltage Research Laboratory of Massachusetts Institute of Technology. Only 2 patients were free of clinical disease in the lower extremities at the time of initial presentation, and 40 patients (69%) had cutaneous lesions involving areas extending above the knees. Eight patients (13%) also presented with mucous membrane involvement in addition to skin disease. Twenty-one patients were treated only with megavoltage electrons during the initial course of radiotherapy, and 12 patients were treated with supervoltage photons alone. The remaining 27 patients were treated with a combination of electrons and photons; in 17 patients, the same tumor sites were irradiated with both modalities. Eleven patients received whole-body surface electron irradiation. The choice of treatment modalities was based on the extent and distribution of cutaneous disease and depth of the lesions. The overall response rate was 93% after a single fractionated course of radiotherapy. Twenty-five patients achieved complete regression and 18 were in remission for 2-13 years. Response rates were also analyzed with respect to the three subgroups in terms of treatment modalities. A single dose of 800 to 1200 rads or its equivalent was required to control local cutaneous lesions. Widespread visceral metastasis was the most common cause of failure and death; the incidence of second malignancies was increased. Trial of systemic chemotherapy and immunotherapy would seem to be a reasonable therapeutic adjunct.