Dosimetric Verification Using Plastic Plates

This study investigates the dosimetric verification of treatment planning system (TPS) calculations using a plastic phantom composed of RW3 slabs.The phantom was scanned with a CT simulator, and treatment plans with different field sizes and gantry orientations were created in the TPS.Dose calculations were performed using both the Collapsed Cone (CC) and Monte Carlo (MC) algorithms.Measurements were carried out with a calibrated Farmer-type ionization chamber connected to an IBA Dose 1 electrometer, with corrections applied for temperature, pressure, and recombination.The comparison between measured and calculated doses showed deviations within 2.2% for CC and 1.8% for MC, well inside the clinical acceptance criterion of 3%.These results confirm the suitability of RW3 slab phantoms for independent dosimetric verification and support the accuracy of both CC and MC algorithms in routine clinical quality assurance.