CT引导下碘125放射性粒子治疗肺癌的剂量学评估

Dosimetry Evaluation of CT-guided Iodine-125 Radioactive Particle in the Treatment of Lung Cancer

目的 探讨CT引导下碘125(^(125)I)放射性粒子治疗肺癌的剂量学评估。方法研究纳入2022年1月至2023年8月中山大学附属肿瘤医院介入科接受CT引导下^(125)I放射性粒子植入治疗的30例晚期肺癌患者。所有患者术前均行胸部CT增强扫描,^(125)I放射性粒子植入术前计划,穿刺及^(125)I放射性粒子植入,放射性活度0.8mCi,处方剂量120Gy。比较CT引导下^(125)I放射性粒子植入术前计划和术后粒子数、临床靶区体积(CTV)、90%靶体积的吸收剂量(D_(90))、100%靶体积的吸收剂量(D_(100))、150%处方剂量覆盖的体积占靶体积的百分比(V_(150))、适形指数(CI)、靶区外体积指数(EI)和均匀性指数(HI)等剂量学参数;Bland-Altman法分析CT引导下^(125)I放射性粒子植入术前计划和术后验证剂量参数的一致性。结果晚期肺癌患者CT引导下^(125)I放射性粒子植入术前计划和术后植入的粒子数、CTV、D_(90)、D_(100)无显著差异(P>0.05);术后V_(150)低于术前计划,差异有统计学意义(P<0.05);患者术后CI较术前减小,EI较术前增高,差异有统计学意义(P<0.05);术前HI与术后比较,差异无统计学意义(P>0.05);经Bland-Altman一致性分析,CT引导下^(125)I放射性粒子植入术前粒子数、CTV和HI的一致性良好,D_(90)、D_(100)、V_(150)、CI、EI的一致性不佳。结论CT引导下^(125)I放射性粒子植入治疗肺癌主要剂量学参数在治疗前后基本吻合,可较好地实现术前计划,满足临床需求。

Objective To explore dosimetry evaluation of CT-guided iodine-125(^(125)I) radioactive particle in the treatment of lung cancer.Methods A total of 30 patients with advanced lung cancer undergoing CT-guided ^(125)I radioactive particle implantation in interventional department of Cancer Hospital Affiliated to Sun Yat-sen University were enrolled between January 2022 and August 2023.All patients underwent chest enhanced CT scan before surgery,^(125)I radioactive particle implantation pre-operation plan,puncture and ^(125)I radioactive particle implantation(radioactive activity:0.8mCi,prescription dose:120Gy).The number of particles,clinical target volume(CTV),the absorbed dose of 90% target volume(D_(90)),absorbed dose of 100% target volume(D_(100)),percentage of volume covered by 150%prescription dose to target volume(V_(150)),conformal index(CI),external index(El) and homogeneity index(HI) before and after surgery were compared.The consistency of dosimetry parameters between preoperative plan and postoperative validation was analyzed by Bland-Altman method.Results There was no significant difference in number of particles,CTV,D_(90) or D_(100) before and after CT-guided ^(125)I radioactive particle implantation(P>0.05).After surgery,V_(150) was decreased(P<0.05).After surgery,CI was decreased,while El was increased(P<0.05).There was no significant difference in HI before and after surgery(P>0.05).Bland-Altman consistency analysis showed that the consistency of particles number,CTV and HI was good,while consistency of D_(90),D_(100),V_(150),CI and El was poor before CTguided ^(125)I radioactive particle implantation.Conclusion The main dosimetry parameters are basically consistent in lung cancer before and after CT-guided ^(125)I radioactive particle implantation,which can better realize preoperative plan and meet clinical demands.