Performance Evaluation of Radiotherapy Treatment Planning System Using the Cirs Thorax Phantom.

Abstract

Treatment Planning System (TPS) authentication is essential for ensuring accurate dose calculations in radiotherapy. This study verified the Varian Eclipse TPS algorithm using a CIRS Thorax phantom, for a 6MV photon beam in conformal radiotherapy. A CT stimulator was used to scan the phantom, and TPS was used to plan eight distinct irradiation geometries simulating conformal radiotherapy. Dose measurements were taken using ionization chambers, and The differences between the measured and computed dosages were examined. The findings demonstrate the variation between measured doses and calculated doses by the TPS were 1.57% and 3.88% respectively within the acceptance criteria of ±5%. The TPS consistently delivered accurate dose calculations even under complex conditions such as oblique incidences and blocked fields. The CT to electron density conversion assessment all measured values within the acceptance criteria of ±20HU.The study validates the Varian Eclipse TPS algorithms’s precision in dose delivery ensuring patient safety. The CIRS Thorax phantom proved competent for the routine TPS verification.