摘要
目的 探讨6MV能量段X线直线加速器Ⅰ、Ⅱ期声门癌三维适形放疗的最佳治疗方案。方法采用三维适形放疗技术治疗Ⅰ、Ⅱ期声门型喉鳞癌患者共9例。采用6MV的高能X线。分别采用双侧水平野加用0°、10°、20°、30°的楔形板，通过TPS获得DVH图及照射野的等剂量曲线分布图．评价后获取最佳治疗方案。对每个患者都做4个治疗计划在各计划完成后，分别对各计划靶区等剂量曲线分布、靶区和正常组织剂量体积直方图（DVH）及适形指数（CI）进行比较。结果①90％的等剂量曲线四种条件下均能覆盖100％的PTV；②不加楔形板、加10°楔形板时，95％的等剂量曲线不能覆盖部分咽喉后部、颈椎椎体前缘，CI低；加20°、30°楔形板，95％等剂量曲线覆盖接近100％的PTV．CI高；③在不加楔形板、加10°、20°楔形板的条件下，100％的等剂量曲线均能覆盖到声门癌好发部位声带前1／3—1／2及侵犯率高的前联合部位，而加30°楔形板时，100％等剂量曲线覆盖体积小，且中心后移，不能覆盖到上述部位。结论早期声门癌在使用6MV高能X线照射时，加用20°的楔形板，95％的等剂量曲线覆盖100%的PIV，CI高，同时100％的等剂量曲线覆盖了声带前1／3—1／2及前联合部位，可获得理想的靶区剂量分析。
Objective To find the optimal therapeutic plan of three-dimensional radiotherapy （3D-CRT） for early glottic cancer （T1-T2 N0M0） using 6MV X-ray. Methods Four 3 D-CRT plans were designed for each 9 patients with T1-T2N0M0 squamous cell carcinoma of the glottis using 6MV X-ray. Parallel-opposed fields were used with open or the 10°, 20°, 30° Wedge respectively. Dose volume histograph （DVH） and the dose distribution of the plan were obtained by treatment planning system （TPS） . We compared the dose distribution, dose volume histograph （ DVH）, eonformity index （ CI）, etc. of the different beam arrangements then fond the optimal therapeutic plan. Results （1） 90% isodose curve in all the four plans could cover 100% of the PTV; （2） with open fields or with the 10° wedge, 95% isodose curve couldn＇ t cover the postzone of pharyngolargnycal or the prozone of cervical vertebrae body, and CI were low; when with the 20° wedge or with the 30° wedge, 95% isodose curve could cove could almost 100% of the PTV, and CI were high. （3） when with open fields or with the 10° , 20° wedge respectively, the 100% isodose curve could cover the anterior 1/3- 1/2 of the chorda vocalis and anterior commissure; when with the 30° wedge, the 100% isodose curve could cover a small beam volume and the center of the beam fields was retrocession, the anterior 1/3-1/2 of the chorda vocalis and anterior commmissure couldn＇t be covered. Conclusion when treating early glottic cancer using 6MV X-ray with the 20° wedge, the 95% isodose curve could cover 100% of the PTV, CI was high, and the 100% isodose curve could cover the anterior 1/3-1/2 of the chorda vocalis and anterior commissure, the dose distribution of target was optimal.
出处
《广州医药》
2006年第1期39-41,共3页
Guangzhou Medical Journal
