The accuracy of single-seed dose superposition for I-125 implants

Abstract

The Monte Carlo method was used to study perturbations of single I-125 seed dose distributions created by the presence of one of three neighboring seeds for the case of seeds immersed in a water phantom. Pertubation factors were determined within the geometric shadow of neighboring seeds for two-seed designs, four-seed spacings, and several choices of dose point. The results were compared to dose estimates obtained by the simple superposition of single-seed data for one- and two-plane implants. Some significant differences were found.