Excellent Response Following Palliative Radiation for Locally Advanced Epidemic/AIDS-Associated Kaposi Sarcoma of the Lower Extremity: A Case Report

<h2>Abstract</h2> Kaposi sarcoma (KS) is a vascular neoplasm caused by an infection with Human Herpes Virus type 8. KS primarily manifests as cutaneous lesions but can involve multiple organ systems in the advanced setting. These lesions can cause multi-system toxicities as well as psychosocial impacts, particularly when prominently located on visible areas. There are four subtypes of KS: Classic, Endemic, Epidemic (AIDS-associated), and Immunosuppression-Associated KS. Classic, endemic, and immunosuppression-associated KS are typically treated with radiotherapy or systemic chemotherapy. AIDS-associated KS management typically involves highly active antiretroviral therapy (HAART), but refractory cases may require additional treatments like radiation therapy for palliation and local control. Although AIDS-associated KS is not commonly treated with radiotherapy, it is equally as radiosensitive as other forms of KS. This report presents a 46-year-old male with a history of HIV/AIDS and KS, both diagnosed seven years prior, with recent progression of KS of the left foot. Despite being treated with HAART and paclitaxel, the patient experienced extensive disease progression over 18 months in the left lower extremity, significant pain, and superimposed infection. Radiation therapy was employed for palliation. A 2-isocenter plan was required given the extent of disease with careful immobilization and daily image guidance. The patient received 30 Gy in 10 fractions, resulting in marked pain relief two weeks following treatment and a significant metabolic response on PET scan. Follow-up revealed sustained pain improvement and lesion response. This case underscores the relative radiosensitivity of KS and the efficacy of palliative radiotherapy in managing even locoregionally extensive disease. While radiotherapy is commonly used for treatment of classic KS, this report advocates for its consideration in advanced AIDS-associated KS management to enhance symptom control and patient outcomes.