CT引导3D打印共面模板辅助^(125)I粒子植入治疗胸壁转移瘤的疗效与剂量学研究

Efficacy and dosimetric analysis of CT-guided ^(125)I seed implantation assisted by 3D-printed coplanar template in the treatment of metastatic tumors of chest wall

目的探讨3D打印共面模板(3D-printed coplanar template,3D-PCT)辅助CT引导125I放射性粒子植入(radioactive 125I seedimplantation,RISI)治疗胸壁转移瘤的技术方法和临床疗效,并分析剂量学参数对疗效的影响。方法回顾性分析2014年1月—2021年3月于滕州市中心人民医院行3D-PCT辅助CT引导125I粒子植入治疗55例胸壁转移瘤临床资料。术前经TPS制定治疗计划,术中在3D-PCT辅助下行125I粒子植入,术后第3天复查CT进行术后剂量验证。术后定期复查CT计算局部控制率、总生存(OS)率,并评价患者疼痛缓解情况及相关并发症。采用Log-rank检验、Cox回归行单因素、多因素分析局部控制时间(local control time,LCT)的影响因素,受试者工作特征(ROC)曲线分析剂量学参数预测LCT的临界值。结果55例行3D-PCT辅助CT引导125I粒子植入治疗的胸壁转移瘤患者术后1、2、3年OS率为72.7%(40/55)、21.8%(12/55)、16.4%(9/55);术后3、6、12、24个月局部控制率为96.4%(53/55)、86.5%(45/52)、85.0%(34/40)、91.7%(11/12)。术后GTV、粒子数目、D_(90)、D_(100)、V_(100)、V_(150)、V_(200)、CI、EI、HI与术前比较差异均无统计学意义(P>0.05);术后V_(90)较术前降低,差异有统计学意义(P=0.006)。单因素Cox回归分析病理分级、D_(90)、D_(100)、V_(90)和V_(200)对LCT有显著影响(P<0.05);将之纳入多因素Cox回归分析后病理分级、D_(90)为LCT独立影响因素,其余因素差异无统计学意义(P>0.05)。Log-rank生存分析显示D_(90)≥127 Gy的患者比D_(90)<127 Gy局部控制时间显著延长(χ^(2)=16.61,P=0.000)。术后3个月疼痛缓解率为80.8%(21/26)。1~2级度放射性皮炎5例,Ⅲ度放射性皮炎1例。结论对于胸壁转移瘤,应用3D-PCT辅助CT引导125I粒子植入剂量精准可控,疗效确切,不良反应少;当D_(90)≥127 Gy时LCT显著延长,D_(90)为LCT的独立影响因素。

Objective To investigate the technical method and clinical efficacy of CT-guided radioactive ^(125)I seed implantation(RISI)assisted by 3D-printed coplanar template(3D-PCT)in the treatment of metastatic tumors of chest wall,and analyze the influence of dosimetric parameters on the treatment efficacy.Methods A retrospective analysis was conducted for 55 patients with metastatic tumors of chest wall treated with 3D-PCT-assisted ^(125)I radioactive seed implantation in Tengzhou Central People′s Hospital from January 2014 to March 2021.Preoperative plans were made using a brachytherapy treatment planning system,and dosimetric parameters were assessed at 3d after surgery.During regular CT reexaminations after surgery,the local control rate and overall survival(OS)rate were calculated and the pain relief degree and complications were assessed.The Logrank test and Cox regression were used for univariate and multivariate analyses of local control time(LCT).Meanwhile,receiver operating characteristic(ROC)curves were plotted to analyze the critical values of dosimetric parameters and to predict the LCT.Results The 1-,2-,and 3-year OS rates ofthe 55 patients were 72.7%(40/55),21.8%(12/55),and 16.4%(9/55),respectively.The local control rates of 3,6,12,and 24 months were 96.4%(53/55),86.5%(45/52),85.0%(34/40),and 91.7%(11/12),respectively.There was no statistically significant difference between postoperative and postoperative dosimetric parameters of GTV,particle number,D_(90),D_(100),V_(100),V_(150),V_(200),CI,EI,and HI(P>0.05).Compared with postoperative V_(90),the postoperative V_(90) decreased with a statistically significant difference(P=0.006).As indicated by the univariate Cox regression analysis,the pathological grade,D_(90),D_(100),V_(90),and V_(200)had significant effects on the LCT(P<0.05).Among them,the pathological grade and D_(90) were independent influencing factors of the LCT,while the other factors showed no statistically significant difference according to the multivariate Cox regression analysis.The LCT of patients with D_(90)≥127 Gy was significantly longer than that of patients with D_(90)<127 Gy(χ^(2)=16.61,P=0.000).The pain relief rate was 80.8%(21/26)after three months.Five cases suffered from gradeⅠ-Ⅱradioactive dermatitis and one case experienced gradeⅢradioactive dermatitis.Conclusions The 3D-PCT-assisted CT-guided ^(125)I radioactive seed implementation can achieve precise and controllable dose and definite efficacy in the treatment of metastatic tumors of chest wall,with few complications.The LCT was remarkably prolonged in the case of D_(90)≥127 Gy,and D_(90) is an independent influencing factor of the LCT.