摘要
目的:比较肝细胞癌常规放疗计划与缩小射束夹角放疗计划在各肝段剂量学指标上的差异,探索缩角策略对肝段剂量分布的影响与临床可行性。方法:纳入29例原发性肝细胞癌患者,首先对每例患者基于Couinaud分段法进行肝脏分段,然后分别制定常规放疗计划与肝段保护放疗计划,处方剂量统一为50 Gy,分25次照射。计划完成后通过电子射野影像装置(EPID)验证每个射野的通过率。在统计分析阶段,按Child-Pugh分级、肿瘤分期、肝段累及范围、肿瘤体积及位置进行亚组间比较剂量学参数,包括每个肝段的平均剂量(Dmean)、V20%、V30%以及靶体积(PTV)的适形度指数(Conformity Index, CI)和D98%等。结果:两计划射束平均γ通过率均≥95%,其中肝段保护(Pro)计划为95.95%,常规放疗(Con)计划为95.80%。在整体组比较中,Pro计划部分肝段实现剂量学改善,V30%在S1(P=0.028)、S6(P=0.009)及S7(P=0.014)均显著降低。进一步的亚组分析显示,T2分期组、Volume>50组、跨肝段组以及右半肝组中S1的V10%、V20%与Dmean显著降低(P<0.05)。在靶区剂量学方面,整体组及大多数亚组中,Pro计划PTV Dmin与D98%显著升高(P<0.05),Dmax与CI显著降低(P<0.05),而PTV Dmean在多数分组中与Con计划接近。结论:缩小射束夹角的肝脏放疗计划在多种临床情境下能够在保证靶区剂量覆盖的前提下降低部分正常肝段的受照剂量,提示在实际放疗中应结合肿瘤所在肝段、肿瘤大小及分期等因素优化射野布置,从而为个体化肝细胞癌放疗策略提供剂量学依据。
Objective To compare the dosimetric differences of each hepatic segment between conventional and beam angle-reduced radiotherapy plans for hepatocellular carcinoma,and to explore the effects of beam angle reduction strategy on the dose distribution of hepatic segments and its clinical feasibility.Methods Twenty-nine patients with primary hepatocellular carcinoma were enrolled.For each patient,liver segmentation was performed using Couinaud's classification,and two radiotherapy plans were generated:a conventional(Con)plan and a hepatic segment-sparing(Pro)plan,both with a prescription dose of 50 Gy delivered in 25 fractions.After plan completion,an electronic portal imaging device was used to verify the passing rate of each field.Dosimetric parameters were compared between subgroups stratified by Child-Pugh classification,tumor stage,hepatic segment involvement,tumor volume,and tumor location.The dosimetric parameters included the mean dose(Dmean),V10%,V20%,and V30%for each hepatic segment,as well as the conformity index and D98%for the planning target volume.Results The field-specific average gamma passing rates were≥95%for both plans,with 95.95%observed in Pro plan and 95.80%in Con plan.In the overall cohort,Pro plan achieved dosimetric benefits in some liver segments,with V30%significantly reduced in S1(P=0.028),S6(P=0.009),and S7(P=0.014).Further subgroup analyses showed that in the T2 stage subgroup,tumor volume>50 subgroup,multi-segment involvement subgroup,and right hepatic lobe subgroup,the V10%,V20%,and Dmean of S1 were significantly decreased(all P<0.05).Regarding target dosimetry,Pro plan significantly increased the Dmin and D98%of PTV(P<0.05),and significantly decreased Dmax and conformity index(P<0.05)in the overall cohort and most subgroups,while the PTV Dmean of Pro plan was comparable to that of Con plan in most subgroups.Conclusion Hepatic segment-sparing plans with reduced beam angles can effectively lower radiation exposure to some normal hepatic segments while maintaining adequate target coverage in various clinical scenarios.These findings indicate that tumor location,size,and stage should be considered when optimizing beam arrangement in clinical radiotherapy,thereby providing a dosimetric basis for personalized radiotherapy planning for hepatocellular carcinoma.
作者
李申超
沈树成
赵汝彬
李需
仇清涛
尹勇
LI Shenchao;SHEN Shucheng;ZHAO Rubin;LI Xu;QIU Qingtao;YIN Yong(Department of Graduate,Shandong First Medical University and Shandong Academy of Medical Sciences,Ji'nan 250117,China;Department of Radiation Physics and Technology,Cancer Hospital of Shandong First Medical University(Shandong Cancer Institute,Shandong Cancer Hospital),Ji'nan 250117,China;Department of Radiotherapy Technology,Beicheng New District Hospital of Linyi People's Hospital,Linyi 276000,China)
出处
《中国医学物理学杂志》
2025年第12期1556-1563,共8页
Chinese Journal of Medical Physics
基金
国家自然科学基金(12275162)。
关键词
肝细胞癌
放疗计划
肝段
射束夹角
剂量评估
hepatocellular carcinoma
radiotherapy plan
hepatic segment
beam angle
dosimetric evaluation
