颈胸交界区食管癌放射治疗中设野方法的研究

Analysis of different field designs applications in radiotherapy for cervical-thoracic esophageal cancer

目的:比较颈胸交界区食管癌放射治疗中不同射野与楔形板应用的技术。方法:采用美国CMS公司XiOV4.1.1三维治疗计划系统(TPS),比较颈胸交界区食管癌在不同治疗计划中等剂量曲线、剂量体积直方图(DVH)及其他评价指标的优劣。结果:采用先前后对穿照射(适形野或马褂野)及后程两前斜野加楔形板治疗技术的剂量分布较仅应用两前斜野加楔形板治疗技术等剂量曲线分布均匀,肺受量减小。运用马褂野较用适形野的照射方式剂量分布更加均匀且满足锁骨上淋巴结区预防照射要求;楔形板常规应用技术(仅厚端相对避免内野高剂量)的靶区剂量分布较其在三维治疗计划系统的应用技术均匀性明显不足。结论:放射治疗技术和楔形板在颈胸交界区食管癌放射治疗中的应用应做到个体化,对锁骨上淋巴结区需预防照射的患者,应采用先前后对穿照射(适形野或马褂野)加后程两前斜野及楔形板治疗技术,对锁骨上淋巴结区不需预防照射的患者,则可以用前两斜野加楔形板治疗技术。

ObjeCtive ：To evaluate the different feld designs and wedge applications in radiation therapy for cervical-thoracic esophageal cancer. Methods：Radiotherapy was designed by US CMS XiO V4.1.1 3-D treatment planning system; Different field designs and wedge applicatioins, including the dose isometric line and DVH etc, were compared. Results： Comparing to the two-field method with wedge by common design and traditional common wedge application, anterior-posterior anomalistic fields was given first, followed by 2-field with wedge application using TPS, the dose distribution in the treatment region is not so uniform or sufficient, and high-dose region existed in the normal issue. Conclusion ：TPS technology is better to design the different optimum combination of wedge parameters for different patients with cervical-thoracic esophageal cancer. It is suggested to use the anterior-posterior anomalistic fields first, then followed by fields with wedge method or the anterior-posterior fields first and followed by two fields with wedge.