A Multimodal Radiation Approach to a Complex Case of Kaposi Sarcoma: Successful Treatment and Long-Term Follow-Up.

Kaposi sarcoma (KS) is an angiogenic tumor frequently seen in HIV-infected patients that involves skin, mucosa, and splanchnic organs. Here, we describe the case of a 57-year-old man with a history of HIV/AIDS on antiretroviral therapy (ART) who presented with KS of the lower extremity. The patient exhibited multiple exophytic lesions circumferentially involving his left leg, causing discomfort and difficulty in activities of daily living. External beam radiation therapy (EBRT) was pursued in lieu of amputation in order to achieve locoregional control while preserving ambulatory function. Due to the extensive longitudinal involvement, the EBRT plan utilized a multi-isocentric volumetric modulated arc therapy (VMAT) technique to cover the entire left leg. The treatment was well tolerated, with a notable response observed in the lesions by the end of the treatment course. Ten weeks following EBRT, new lesions appeared within the previously treated fields on the left foot. These were treated using high dose-rate (HDR) brachytherapy with a custom skin mold. The patient experienced Grade 3 skin toxicity from treatment, but wound care management led to complete skin regrowth. A second course of HDR brachytherapy was used to treat additional lesions on the mid thigh with no subsequent acute toxicities. Over eight years since initial treatment, the patient has shown no recurrence in the treated areas and remains disease-free. This case illustrates the efficacy and potential long-term benefits of a hybrid multimodal radiation therapy approach in managing KS lesions in patients with HIV/AIDS, particularly when surgical options are limited.