Rapidarc联合呼吸门控在非小细胞肺癌放疗中的应用

目的：探讨RapidArc联合呼吸门控技术在非小细胞肺癌放射治疗中的应用。方法：选取未能手术的ⅢA-ⅢB期非小细胞肺癌患者19例,分别在自由呼吸（FB）和呼吸门控系统RC状态下为每例患者设计FB下的IMRT（IMRT-FB）、双弧RapidArc（Arc-FB）和RC下的IMRT（IMRT-RC）、双弧RapidArc（Arc-RC）4种放疗计划。评价四种计划和Arc-RC治疗的疗效及副反应。结果：除1例患者由于经济原因中途退出,其他患者均顺利完成治疗。PTV的平均体积由FB下的296 cm3减少到了RC下的210.2cm3；RC下的双肺平均体积为3817.4 cm3,较FB增加了34%；Arc-RC计划靶区的CI、HI及D2%、D98%、V95,与IMRT-FB、Arc-FB、IMRT-RC计划差异无统计学意义,但双肺的V20、V30、V40、V50、及平均剂量（Dmean）明显低于后三者（P〈0.05）。总有效率为72.23%（13例）。急性放射性食管炎1、2级发生率分别为61.1%、16.7%,急性放射性肺炎1、2级发生率分别为77.8%、11.1%,骨髓抑制1、2、3级分别为61.1%、22.2%、11.1%,急性心脏损伤1、2级发生率分别为83.3%、16.7%。结论：RapidArc联合呼吸门控在非小细胞肺癌精确放疗中具有减少正常组织受照剂量体积和提高放疗精度的作用。

Application of Rapid arc Combined Respiratory Gating in the Radiotherapy of Non-small Cell Lung Cancer

Objective： To investigate the application of RapidArc combined respiratory gating technique in the radiotherapy of non-small cell lung cancer. Methods： Nineteen inoperable Ⅲ A- Ⅲ B non-small cell lung cancer patients were selected under free breathing（FB） and respiratory gating system（RC） stater espectively, four kinds of radiation treatment planning for each patient were designed： under FB IMRT（IMRT-FB）, double arc RapidArc（Arc-FB） and under RC IMRT（IMRT-RC）, double arc RapidArc（Arc-RC）.The efficacy and side effects of four plans and Arc-RC were evaluated. Results： Except one patient dropped out due to economic reasons,other patients were successfully treated.The average volume of PTV reduced from 296cm3 under the FB state to 210.2cm3 under the RC state; The average volume of lung was 3817.4cm3 under the RC, an increase of 34% the FB;The CI, HI and D2%, D98%, V95 of Arc-RC planning target volume, compared with IMRT-FB, Arc-FB, IMRT-RC plan had no significant difference, but V20, V30, V40, V50, and the average dose（Dmean） of the lungs was significantly lower than the latter three（P0.05）. The total effective rate was 72.23%（13 cases）.The rates of acute radiation esophagitis 1,2-level were 61.1%, 16.7%; The rates of acute radiation pneumonitis 1,2-level were 77.8%,11.1%; the rates of myelosuppression 1,2,3-level were 61.1%, 22.2%, 11.1%, and the rates of acute cardiac injury 1,2-level were 83.3%,16.7%. Conclusion： RapidArc combined respiratory gating accurate in non-small cell lung cancer radiotherapy can reduce the volume of normal tissue radiation dose and increasing the role of radiotherapy precision.