鼻咽癌三维适形放射治疗中质量控制的分析

目的：分析鼻咽癌三维适形放射治疗中的质量控制。方法：使用BJ-66MV单光子直线加速器，STAR-2000三雏治疗计划系统和定位头架对鼻咽癌患者行放射治疗。结果：使用面罩固定方式固定体住，采用2mm层厚、2mm层距的CT扫描，获取靶区及其周围组织的三维数据，并设计三维适形放疗计划。在加速器上通过摆位将靶区置于等中心实施放射治疗。结论：鼻咽癌所处部位特殊，临近很多关键器官，因此在三维适形放疗中，必须对CT定位和治疗摆位的过程进行严格的质量控制，保证较小的靶体积给予有效和安全的剂量照射，同时避免对周围重要器官的过量照射．减少并发症的发生。

Analysis on Quality Control of Conformal Radiotherapy for Nasopharyngeal Carcinoma

Objective To analyze the quality control of the conformal radiotherapy for nasopharyngeal carcinoma. Methods Using BJ-6 6MV linear accelerator, STAR -2000 3D TPS and immobilization device, the patient of nasopharyngeal carcinoma were treated by the conformal radiotherapy. Results Adopting individualized compatibly-shaped face masks and CT scanning (2mm interval, 2mm thickness), three dimensional data of the target and the other tissues were acquired. The conformal radiotherapy was designed in planning system. At the treatment, the target volume was put on the isocenter of the linear accelerator by the customized patient positioning. Conclusion Because the nasopharyngeal carcinoma is located in a special area and it is surrounded by some important organ, in the conformal radiotherapy, the quality control of the CT immobilization technique and the customized patient positioning is very important. This can ensure effective and safe irradiation for the small target volume while excessive irradiation is avoided in other surrounding organs.