【摘要】 目的 探讨呼吸触发前瞻门控在早期非小细胞肺癌（NSCLC）立体定向放射治疗（SBRT）中剂量学优势。方法 选取21例经病理证实的早期NSCLC患者，分别行自由呼吸下3D-CT、4D-CT电影模式和呼气末前瞻性呼吸触发轴向-R模式扫描，同等条件下分别设计前瞻门控(Plan_pro)、30%～70%时相回顾门控(Plan_30-70)、运动包络法(Plan_all)及传统基于人群边际的3D-CT(Plan_3D)4组无均整器模式容积旋转调强SBRT计划。统计分析计划靶体积（PTV）、患侧肺和全肺的V₅、V₂₀、V_14.4、平均肺剂量（MLD）、全肺正常组织并发症概率（NTCP）、心脏D_max、食管D_max、食管NTCP、脊髓D_max和近端支气管树D_max等指标。结果 Plan_all与Plan_3D相比，除脊髓D_max的所有剂量学参数均下降差异有统计学意义（P<0.05）。与Plan_all相比，Plan_pro的PTV、患侧肺V₅、V₂₀、V_14.4、MLD、全肺V₅、V₂₀、V_14.4、MLD、NTCP、心脏D_max和食管NTCP较Plan_30-70分别进一步减少了8.42 cc、2.06%、1.02%、26.67 cc、0.58 Gy、2.35%、0.63%、32.89 cc、0.43 Gy、0.1%、1.72 Gy及0.09%，差异有统计学意义（P值分别为0.004、<0.010、0.006、0.010、0.006、0.004、<0.001、0.010、<0.001、0.005、<0.001、0.026）。结论 早期NSCLC SBRT中，传统基于人群边际的3D-CT计划高估PTV并增加危及器官受量；采用呼吸运动管理技术，尤其是前瞻门控更好保护胸部正常组织器官，减少患者放疗不良反应。更多还原

【Abstract】 Objective To investigate the dosimetric advantages of respiratory-triggered prospective gating in stereotactic body radiation therapy（SBRT） for early-stage non-small-cell lung cancer（NSCLC）.Methods A total of 21 patients with pathologically confirmed early-stage NSCLC were selected and received free-breathing 3DCT,4D-CT cine mode and end-expiratory prospective respiratory-triggered axial-R mode scans,respectively.With FFF,VMAT and SBRT technology under the same condition,four corresponding plans,prospective gating(Plan_pro),30%～70% temporal retrospective gating(Plan_30-70),motion enveloped method(Plan_all) and conventional population margin-based 3D-CT(Plan_3D) were designed,respectively.The planning target volume（PTV）,the V₅,V₂₀,V_14.4,MLD of both ipsilateral lung and bilateral lung,the normal tissue complication probability（NTCP） of the bilateral lung,heart D_max,esophagus D_max,the NTCP of the esophagus,spinal cord D_max and proximal bronchial tree D_max were compared.Results Statistically significant differences were found between Plan_all and Plan_3D for all dosimetric parameters except spinal cord D_max（P <0.05）.Compared with Plan_all,Plan_pro showed further reductions in PTV,ipsilateral lung V₅,V₂₀,V_14.4,MLD,bilateral lung V₅,V₂₀,V_14.4,MLD,NTCP,heart D_max and esophagus NTCP compared to Plan_30-70 by 8.42 cc,2.06%,1.02%,26.67 cc,0.58 G_y,2.35%,0.63%,32.89 cc,0.43 G_y,0.1%,1.72 Gy and0.09%（P=0.004,<0.010,0.006,<0.001,0.006,0.004,<0.001,0.010,<0.001,0.005,<0.001,0.026）.Conclusion In SBRT for early-stage NSCLC,conventional population margin-based 3D-CT plans overestimated PTV and increased the exposure dose to organs at risk;respiratory motion management technologies,especially prospective gating,could better protect normal tissues and organs in the chest and reduce adverse effects of radiotherapy.更多还原