电场治疗联合放疗中贴片阵列对放疗剂量学的影响  

Impact of tumor treating fields transducer arrays on concurrent radiotherapy dosimetry

作　　者：王克强[1] 陈杰[1] 简建波 王鹏[1] 张鑫山 张弘扬 张文学[1] Wang Keqiang;Chen Jie;Jian Jianbo;Wang Peng;Zhang Xinshan;Zhang Hongyang;Zhang Wenxue(Department of Radiation Oncology,Tianjin Medical University General Hospital,Tianjin 300052,China)

机构地区：[1]天津医科大学总医院放射治疗科,天津300052

出　　处：《中华放射肿瘤学杂志》2024年第5期438-445,共8页Chinese Journal of Radiation Oncology

基　　金：吴阶平医学基金(320.6750.17137、320.6750.2020-18-3)。

摘　　要：目的研究胶质母细胞瘤(GBM)电场治疗(TTF)的电场贴片阵列对同步放疗的剂量学影响。方法构建TTF阵列对放疗剂量影响的准确模拟计算策略,包括建立TTF阵列的准确勾画方法、确定TTF阵列的相对电子密度(RED)及验证治疗计划系统(TPS)剂量算法对TTF阵列的计算精准性。在此基础上,评估TTF阵列对10例GBM患者临床放疗计划的剂量学影响;进而比较不同能量射束在佩戴TTF阵列放疗中的剂量学差异。差异分析根据差值是否服从正态分布选择配对t检验或Wilcoxon符号秩检验。结果通过设计Mim工作流,实现了TTF阵列的自动勾画,勾画结果和标准勾画相比,戴斯相似性系数为0.93,Jaccard相似系数为0.87。对比TTF阵列对百分深度剂量(PDD)影响的测量结果和TPS模拟结果,确定了TTF阵列的RED为3.3。对不同深度面剂量的测量结果和TPS计算结果进行γ分析,发现在3%/3 mm标准下,4 mm和5.1 cm深度的γ通过率分别为96.64%和94.55%,表明TPS剂量算法对TTF阵列的计算准确性可以满足临床需要。在GBM临床放疗计划中,TTF阵列会使靶区剂量降低1%左右,头皮剂量升高约5%,而对其他危及器官影响很小。佩戴TTF阵列时,10 MV放疗计划的靶区剂量比6 MV计划高0.3%,而头皮剂量比6 MV计划低3%左右。结论本研究构建的TTF阵列对放疗剂量影响的准确模拟策略可以保证模拟计算的精准性,在GBM电场治疗联合放疗中,TTF阵列对靶区剂量影响不大,但会显著增加头皮剂量,而高能射束可以降低TTF阵列的影响。Objective To investigate the dosimetric impact of tumor treating fields(TTF)transducer arrays on concurrent radiotherapy for patients with glioblastoma(GBM).Methods A strategy was developed to accurately simulate the dosimetric impact of TTF arrays on radiotherapy,including the establishment of accurate auto-segmentation technique for TTF arrays,determination of the relative electron density(RED)of the transducer arrays and validation of the dose calculation accuracy in the treatment planning system(TPS)for TTF arrays.Based on this strategy,the dosimetric impact of TTF arrays on clinical treatment plans of 10 patients with GBM was evaluated.Furthermore,the dosimetric comparison between the clinical plans with different beam energies were investigated when TTF arrays were used.The methods of analysis of variance were paired t-test or Wilcoxon signed-rank test based on whether the differences followed a normal distribution.Results The auto-segmentation technique for TTF arrays was established by designing a workflow in Mim software and achieved a Dice coefficient of 0.93 and a Jaccard index of 0.87 compared to the standard contours.The RED of TTF arrays was 3.3 which was derived from the comparison between the measured and simulated percentage depth dose(PDD)with and without TTF arrays on phantom.Measured and calculated dose distributions were compared using the 2D gamma analysis.The gamma passing rates on the coronal plane of 4 mm and 5.1 cm depth were 96.64%and 94.55%at the criteria of 3%/3 mm,indicating that the calculation accuracy of algorithm in TPS for TTF arrays could meet clinical requirements.In the clinical treatment plans of patients with GBM,the presence of TTF arrays caused a mean reduction of planning target volume(PTV)dose of approximately 1%,and an increase in scalp dose of approximately 5%,with minimal impact on other organs at risk(OAR).The 10 MV plans resulted in a higher dose of PTV by 0.3%and lower dose of scalp by approximately 3%compared to the 6 MV plans,when considering TTF arrays.Conclusi

关 键 词：放射疗法 肿瘤电场治疗 电场贴片阵列 自动勾画 相对电子密度 射束能量 

分 类 号：R730.55[医药卫生—肿瘤]