Method for assessing the accuracy of source positioning during brachytherapy

Abstract

A method for assessing the accuracy of source positioning using a new phantom for quality control procedures of applicators in brachytherapy is presented. A description is given of a phantom for performing measurements as part of quality control procedures for brachytherapy applicators, which are placed in the phantom in the form of a rod at a distance of 2–4 cm from the location of the ionization chamber. The air kerma strength was measured and the distance from the source to the ionization chamber was calculated. The measured values of the distances were compared with the values obtained by measuring the X-ray images of the applicator with a source located in it or radiopaque markers. The parameters recorded using the developed phantom are in good agreement with the parameters obtained using the X-ray machine installed in the procedural room (p > 0.05). The use of the proposed phantom will allow not only determination of the accuracy of the radiation source position in the applicator channel, but also verification of the irradiation plans for various types of applicators, including the use of shielding blocks.