Application of electronic beam irradiation technology of L shape field in the traditional radiotherapy of nasopharyngeal carcinoma / 肿瘤研究与临床

Objective To introduce a new way to solve the problem of field-field junction in the traditional radiotherapy of the nasopharyngeal carcinoma better.Methods Using the 3-dimentional planning system,the dose distribution of traditional radiotherapy and the electronic beam irradiation technology of L shape field for nasopharyngeal carcinoma in 2D-or 3D-CRT could be gotten.Results The dose coverage of V95 of the gross tumor volume(GTV)satisfied the clinical requirements.The highest dose in the electronic beam irradiation of L shape field was 7200 cGy,while it was 8900 cGy in the traditional way.The volume of dose that over 6500 cGy of throat was 19.64 ％ in the former,the latter was 31.95 ％.Conclusion The electronic beam irradiation technology of L shape field is better than the traditional radiotherapy in field-field junction and in dose distribution.Since that,the electronic beam irradiation technology of L shape field is worth of application for the treatment of nasopharyngeal carcinoma.

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

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.