3D打印个体化模板联合CT引导^(125)I粒子植入治疗肿瘤术前术后剂量学比较

A dosimetric study of 3D print individual template combination with CT-guided ^(125)I seed implantation for malignant tumors

目的比较3D打印个体化模板联合CT引导^(125)I粒子植入术后验证与术前计划剂量学参数的差异,探讨其在剂量学中的作用。方法收集2016年2月至10月住院患者37例,对每例患者设计3D打印个体化模板。在3D打印个体化模板引导下进行粒子植入手术,术后即刻行CT扫描并进行剂量学验证。比较手术前后植入参数和剂量学参数。结果 37例患者模板均成功设计打印。术前临床靶体积(CTV)的范围是5.9~133.1 cc,平均为(36.1±31.3)cc;术后验证CTV范围是5.9~133.6 cc,平均(37.1±36.6)cc,两者比较差异有统计学意义(P<0.001)。处方剂量为100~160 Gy。术前计划粒子数为18~80颗,术后实际植入粒子数为24~84颗,其中2、6、12、14、15、21号患者分别补植了1~9颗不等的粒子。术前计划D90范围107.1~187.8 Gy,平均(144.7±18.8)Gy,术后验证D90范围是103.9~189.3 Gy,平均(143.3±20.3)Gy,两者比较差异无统计学意义(P=0.06)。术前计划V100的范围是83.7%~99.9%,平均(96.4±3.1)%,术后验证V100范围是85.2%~100%,平均(96.9±3.3)%,两者比较差异有统计学意义(P=0.002)。结论 3D打印个体化模板联合CT引导粒子植入治疗恶性肿瘤能够保证术后剂量学指标的质量控制,但术前计划剂量学分布与术后验证仍存在一定差异,多方面原因及经验需继续分析总结。

Objective To explore the use of 3D print individual template and CT-guided^（125）I seed implantation in dosimetry by comparing the parameters before and after implantation. Methods A total of 37 patients treated during Feb.and Oct. 2016 were involved. Before implantation,all patients underwent CT scan and the data were saved in digital imaging and communications in medicine（ DICOM） format. The individual template was designed by brachytherapy treatment planning system（ BTPS）,and printed by 3D print technique. Patients received^（125）I seeds interstitial implantation with the guide of individual template and CT. After implantation,CT scan was performed immediately for dosimetric verification. The pre-and post-operative parameters were compared. Results All 37 individual templates were successfully designed and printed. The range of clinical target volume（ CTV） was 5. 9-133. 1 cc[averaged（ 36. 1 ± 31. 3）cc] vs 5. 9-133. 6 cc[averaged（ 37. 1 ± 36. 6） cc]in preplan and post implantation,and there was significant difference（ P〈0. 001）. The prescription dose（ PD） was 100-160 Gy. The numbers of preplan seeds and actually implanted seeds were 18-80 vs 24-84. Patients No. 2,6,12,14,15,and 21 received 1-9 complemented seeds during the surgery. The range of D90 was 107. 1-187. 8 Gy[averaged（ 144. 7 ± 18. 8） Gy] vs 103. 9-189. 3 Gy[averaged（ 143. 3 ± 20. 3） Gy]in preplan and post implantation,and there was no significant difference（ P = 0. 06）. The range of V100 was 83. 7%-99. 9% [averaged（ 96. 4 ± 3. 1） %] vs 85. 2%-100% [averaged（ 96. 9 ± 3. 3） %] in preplan and post implantation,and there was significant difference（ P = 0. 002）. Conclusion 3D print individual template and CT-guided^（125）I seed implantation can ensure the dosimetric quality control in the treatment of malignant tumors,but there are some differences between the preplan and postoperative parameters. Therefore,more clinical experiences still need to be summarized and analyzed.