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

Objective was to evaluate the dose-response relationship in classical Kaposi's sarcoma CKS patients treated with external beam radiotherapy. Between 1993 and 2004, patients with CKS treated at the Department of Radiation Oncology, Gulhane Military Medical School, Ankara, Turkey were evaluated in this retrospective study. The median age at initial presentation was 60 years. First we analyzed the overall response rates for normalized total dose2Gy NTD2Gy of <20Gy, = 20Gy and >20Gy. Secondly we searched for whether better response rates could be obtained with the NTD2Gy of >/=20Gy compared to the NTD2Gy of <20Gy. 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 NTD2Gy of < 20Gy, 97% for 20 Gy and 96% for NTD2Gy, which were not statistically different. The complete and partial response rates at 12 months were 93.2% and 3.4% for NDT2Gy of >/20Gy and 64% and 24%for NDT2Gyof 20< Gy and these were statistically different p=0.001. Late side effects of radiation therapy were acceptable in all but 4 patients with fibrosis and edema. This retrospective analysis showed that radiotherapy schedules with an NDT2Gy 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 NDT2Gy of < 20 Gy. (author)