Dosimetric verification of two commercially available three-dimensional treatment planning systems using the TG 23 test package.

Abstract

The Task Group 23 (TG-23) radiation treatment planning dosimetry verification package was used to evaluate the dosimetric accuracy of two commercially available treatment planning systems. The TG-23 test package contains experimentally measured beam data for two x-ray beams (4 and 18 MV) that can be used as input for 3D-RTP (three-dimensional radiation treatment planning) systems. Once the beam data is entered and modeled, a series of test cases are performed that isolate different aspects of the dose computational process. The computed values from the 3D-RTP system are compared against the measured dosimetry data, included in the package, for a set of comparison points within each test case. Both of the treatment planning systems that were studied provided excellent agreement between computed and measured doses. The cumulative 4 and 18 MV TG-23 test results for the convolution/superposition based planning system indicates that 96% of the dosimetric test points are within +/-2%, and 98% are within +/-3% of the tabulated TG-23 values. The dosimetric TG-23 test results for the pencil beam kernel based planning system are similar, with 96% of the test points falling within +/-2%, and 99% falling within +/-3% of the TG-23 measurements.