The Application Study of the TBI Simulation of Three Dimension Treatment Planning System / 中国医学物理学杂志

ABSTRACT

Purpose: Simulating calculation the dose distribution of the total body irradiation (TBI) with three dimension treatment planning system(3D-TPS ). Materials and Methods: For TBI, the source skin distance(SSD) is 380 cm, field size is 40 cm × 40cm, and collimator angle is 45°. The percent dose depth (PDD) and onset axis ratio (OAR) of the linac accelerator is measured with the big water phantom self-made. In the same radiation condition, the PDD and OAR of water which is simulated calculation with the 3D-TPS is compared with the measurement results to confirm whether the 3D-TPS can calculate the TBI dose distribution. The dose distribution of the human phantom is calculated with 3D-TPS, which is compared and confirmed with the film and TLD measurements. Results: The maximum error of PDD and OAR in the water phantom between the measurements and calculations of 3D-TPS are 3% and 6%. The calculation results of the 3D-TPS is according with the measurement results of the film and TLD approximately. Conclusions: 3D-TPS could simulate calculation the dose distribution for TBI accurately. It is possible to improve more uniform dose for TBI with corresponding compensator for specific patient.