125I粒子治疗恶性肺肿瘤所致放射性肺炎剂量学因素分析

Dosimetric analysis of radiation pneumonitis induced by 125 I seed implantation for the treatment of malignant lung tumors

目的观察125I粒子植入治疗恶性肺肿瘤导致放射性肺炎发生率,对其相关剂量学参数进行分析。方法回顾分析2017年1月至2022年12月河北省肿瘤放射性粒子植入诊疗中心收治的31例接受125I粒子植入治疗的恶性肺肿瘤患者,其中鳞癌8例,腺癌10例,其他部位转移癌13例,术后1~6个月复查胸部CT,采用实体瘤疗效评价标准(RECIST 1.1)对所有患者行疗效评价,观察客观缓解率(ORR)及疾病控制率(DCR),放射性肺炎(RP)采用美国肿瘤放射治疗协作组(RTOG)放射性肺炎评价标准评价,统计术后D90(90%靶体积所接受的最小周边剂量)、患侧肺V_(8)(8 Gy包绕肺体积占患侧肺体积的百分比)、V_(32)(32 Gy包绕肺体积占患侧肺体积的百分比)、患侧肺Dmean(平均照射剂量)。分析术后D_(90)、V_(8)、V_(32)、Dmean等剂量学参数与发生RP的关系,将术后各剂量学参数与外放疗相关数据进行比较,寻找与RP发生相关性较高的参数。结果所有患者均顺利手术,术后6个月疗效评价完全缓解(CR)11例,部分缓解(PR)11例,疾病稳定(SD)8例,疾病进展(PD)1例,ORR为71.0%,DCR为96.8%,RP患者3例,RP发生率为97%,粒子术后V_(8)、V_(32)、D_(mean)等不能作为预测放射性肺炎指标,经随访观察术后D90超过170 Gy发生放射性肺炎患者3例(3/5),<170 Gy患者发生放射性肺炎患者0例(0/26)。结论粒子植入治疗恶性肺肿瘤,术后D_(90)与RP发生有一定相关性,V_(8)、V_(32)、D_(mean)与RP发生无相关性。

Objective To investigate the incidence of radiation pneumonitis(RP)induced by 125 I seed implantation for the treatment of malignant lung tumors and analyze related dosimetric parameters.Methods A retrospective analysis was conducted on 31 cases of malignant lung tumors treated with 125 I seed implantation from January 2017 to December 2022 at Hebei Provincial Tumor Radioactive Seeds Implantation Diagnosis and Treatment Center.These cases consisted of eight patients with squamous cell carcinoma,10 patients with adenocarcinoma,and 13 patients with metastatic cancer in other sites.At 1-6 months after treatment,these patients received postoperative chest CT scans,with the efficacy evaluated based on the Response Evaluation Criteria in Solid Tumors version 1.1(RECIST 1.1),including the objective response rate(ORR)and the disease control rate(DCR).The efficacy of RP was evaluated using the Radiation Therapy Oncology Group(RTOG)criteria.Postoperative dosimetric parameters,including D_(90)(minimum peripheral dose received by 90% of the target volume),V_(8)(percentage of lung volume receiving 8 Gy),V_(32)(percentage of lung volume receiving 32 Gy),and D_(mean)(mean radiation dose)of the affected lung,were statistically analyzed.The relationships of the RP occurrence with postoperative D_(90),V_(8),V_(32),and D_(mean) were analyzed by comparison with relevant external radiotherapy data,to identify the parameters that are correlated closely with RP occurrence.Results All the patients underwent successful surgeries.The postoperative efficacy evaluation after six months showed complete response(CR)in 11 cases,partial response(PR)in 11 cases,stable disease(SD)in eight cases,and progressive disease(PD)in one case,with an overall response rate(ORR)of 710%,and a disease control rate(DCR)of 968%.Three patients suffered RP,with an incidence rate of 97%.Postoperative V_(8),V_(32),and D_(mean) could not serve as predictive indicators for RP.Follow⁃up observation revealed that three RP cases(3/5)exhibited postoperative D_(90) exceeding 170 Gy and no RP cases(0/26)showed postoperative D_(90) below 170 Gy.Conclusions In the treatment of malignant lung tumors with 125 I seed implantation,there is a certain correlation between RP and postoperative D_(90),while there is no correlation between it and V_(8),V_(32),and D_(mean).