The Design of an Audit Test for 60Co Brachytherapy Treatment Planning System

Background: auditing the treatment planning system (tps) software for a radiotherapy unit is of paramount importance in any radiation therapy department. a plexiglas phantom was proposed to measure the ionization of 60co high dose rate (hdr) source and compare dose points in the planning system for auditing and verifying tps. methods: auditing was performed using a plexiglas phantom in an end‑to‑end test, and relative dose points were detected by a farmer‑type ionization chamber and compared with the relative dose of similar points in tps. the audit results were determined as pass optimal level (<3.3%), pass action level (between 3.3% and 5%), and out of tolerance (>5%). results: the comparison of the collected data revealed that 80% of the measured values were ≤5% in the pass level, and 20% of the points were out of tolerance (between 5% and 6.99%). conclusion: this study documented the appropriateness of the dosimetry audit test and this phantom design for the hdr brachytherapy tps.