High dose rate Microselectron moulds for Kaposi sarcoma of the palate.

Abstract

External beam radiotherapy for Kaposi sarcoma of the palate in HIV positive patients has often severe acute side-effects. As alternative treatment, a high dose Microselectron brachytherapy technique was developed. A customised dental plate with afterloading tubes was made; from outlines, three dimensional coordinates of source positions and surface points were input to a Target 2 treatment planning computer. For the best dose-distribution on the mould surface, weighting of each source dwell position was adjusted, a plan produced, and a test run with TLD measurements performed. We planned and treated six patients and seven lesions with this technique. A median surface dose of 24 Gy (range 14-39.9 Gy) in 3 fractions over 3 to 10 days was prescribed. There was a complete response for all lesions with only mild mucositis. No relapse occurred in the treated areas. Kaposi sarcoma of the palate treated with a high dose rate Microselectron dental plate is convenient for the patient, achieves local control and has less acute toxicity compared with external beam radiotherapy.