A dose-response analysis for classical Kaposi's sarcoma management by radiotherapy

Objectives: To evaluate the dose-response relationship in classical Kaposi's sarcoma (CKS) patients treated with external beam radiotherapy. Methods: Between 1993 and 2004, patients with CKS treated at the Department of Radiation Oncology, Gulhane Military Medical School, Ankara, Trurkey were evaluated in this retrospective study. The median age at initial pre,4en.taxion was 60 yeas. First, we analyzed the overall response rates for normalized total dose 2Gy of (NTD)_2Gy) of <20 Gy, 20 Gy, and >20 Gy. Secondly, we searched for whether better response rates could be obtained with the NTD_2Gy of ≥20 Gy compared to t lie NTD_2Gy of <20 Gy. Results: There were 109 evaluable lesions in 18 patients. The median follow-up was 4 years. The overall response rates at: the post-radiotherapy twelfth month were 88% for NTD of <20 Gy, 97% for 20 Gy, and 96% for NTD_2Gy> 20 Gy, which were not statistically different, The complete and partial response rates at 12 months were 93.2%, and 3.4% for NTD_2Gy of ≥20Gy, and 64% and 24% for NTD_2Gy of <20 Gy and these were statistically different (p=0,001), Late side effects, of radiation therapy were acceptable in all but 4 patient with fibrosis and edema. Conclusion: This retrospective analysis showed that radiotherapy schedules with an NTD_2Gy of 20 Gy and above by using local irradiation fields are effective in terms of complete response rates in the management of CKS compared to NTD_2Gy of <20 Gy.