Atypical radiation toxicity in patients with classical Kaposi's sarcoma

The classical (non-AIDS-related) form of Kaposi's sarcoma (KS) typically affects older patients of Eastern European or Mediterranean ethnic background. Although radiotherapy is a standard part of the treatment armamentarium for KS patients, a high incidence of radiotoxicity has been reported in epidemic AIDS-related cases. In order to determine whether this radiotoxicity is observed only in patients with the epidemic form of the disease, we have conducted a retrospective chart review of 30 patients with classical KS treated with radiation for whom follow-up information was available. Seven out of 30 (23%) were found to have unexpectedly high levels of radiotoxicity after tumor doses of 22-42 Gy. This toxicity consisted either of significantly increased edema or chronic skin breakdown and severe radiodermatitis, in some cases requiring multiple surgical corrective procedures. We suggest that the abnormal lymphaticovenous development and chronic lymphokine stimulation associated with KS of both epidemic and classical forms may be responsible in part for the observed radiotoxicity.