基于盆腔MRI图像的新型直肠腔内施源器的设计与评价  

Design and evaluation of a novel arcuate multi-channel rectal endoluminal applicator based on pelvic MRI images

作　　者：程天 廉清杰 彭冉[2] 孙海涛[1,2] 曲昂[1,2] 王皓[1] Cheng Tian;Lian Qingjie;Peng Ran;Sun Haitao;Qu Ang;Wang Hao(Cancer Center,Peking University Third Hospital,Beijing 100191,China;Department of Radiation Oncology,Peking University Third Hospital,Beijing 100191,China;School of Medical Imaging,Hebei Medical University,Shijiazhuang 050031,China)

机构地区：[1]北京大学第三医院肿瘤中心,北京100191 [2]北京大学第三医院肿瘤放疗科,北京100191 [3]河北医科大学医学影像学院,石家庄050031

出　　处：《中华放射肿瘤学杂志》2024年第11期1042-1048,共7页Chinese Journal of Radiation Oncology

基　　金：国家临床重点专科建设项目(2021);北京大学第三医院创新转化基金(BYSYZHZB2022109)。

摘　　要：目的设计并评价一种新型弧形多通道直肠腔内施源器,以增强对直肠中上段肿瘤的剂量覆盖并降低对直肠壁的压强。方法回顾性分析2022年7月至2022年8月北京大学第三医院200例中国无直肠病变人群盆腔MRI图像,基于图像数据设计并制造了具有人群一般特征的直肠体模与硬软两类材质的新型弧形施源器。对比常规直筒施源器和两种新型弧形施源器对体模直肠壁的形变、最大压强与稳定压强,以及GTV的D_(90%)、D_(100%)、V_(100%)、V_(150%)、V_(200%)和危及器官的D_(2 cm^(3))、D_(1 cm^(3))、D_(0.1 cm^(3))。采用方差分析或Kruskal-Wallis H检验比较三组施源器差异,Dunnett多重比较检验进行配对比较。结果硬软两类材质的新型弧形施源器造成体模肠壁的形变均较小。硬质弧形施源器和软质弧形施源器对直肠壁的最大压强分别为(0.606±0.182)kPa、(0.481±0.229)kPa,稳定压强分别为(0.207±0.137)kPa、(0.055±0.097)kPa,均显著小于直筒施源器(P<0.001、<0.001,P=0.024、<0.001),降幅达到或接近50%。在确保靶区剂量的前提下,硬质弧形施源器和软质弧形施源器设计计划中的危及器官的D 2_(cm^(3))、D_(1 cm^(3))、D_(0.1 cm^(3))比直筒施源器显著降低(均为P<0.001)。结论新型弧形多通道直肠腔内施源器可显著降低直肠壁压强和形变,同时能在不牺牲靶区剂量覆盖的情况下降低危及器官的剂量,有一定的治疗优势。Objective To design and evaluate a novel arcuate multi-channel rectal endoluminal applicator to enhance dose coverage of tumors in the upper and middle rectum and reduce pressure on the rectal wall.Methods Pelvic MRI images of 200 Chinese cases without rectal lesions in the Peking University Third Hospital from July 2022 to August 2022 were retrospectively analyzed.Based on the image data,a rectal model with general characteristics of the population and two novel hard and soft rectal endoluminal applicators were designed and fabricated.The following properties of the conventional applicators and two new applicators were compared:deformation to the model rectal wall,maximum pressure,stable pressure,D_(90%),D_(100%),V_(100%),V_(150%)and V_(200%)of the GTV,and D_(2 cm^(3)),D_(1 cm^(3)),and D_(0.1 cm^(3)) of the organs at risk(OAR).ANOVA or Kruskal-Wallis H-test was used to compare the differences among three applicators,and Dunnett's multiple comparison test was used for pairwise comparisons.Results The novel hard and soft rectal endoluminal applicators caused less deformation of the model rectal wall.The maximum pressure on the rectal wall was(0.606±0.182)kPa and(0.481±0.229)kPa for the hard arcuate applicator and soft arcuate applicator,respectively,and the stable pressure was(0.207±0.137)kPa and(0.055±0.097)kPa,respectively,which were significantly smaller than those of the conventional applicator(P<0.001,<0.001;P=0.024,<0.001),and the degree of reduction was at or near 50%.Under the premise of ensuring target dose,the D_(2 cm^(3)),D_(1 cm^(3)),and D_(0.1 cm^(3)) of OAR in the treatment plan designed with the novel applicator were significantly reduced compared to the cylindrical applicator(all P<0.001).Conclusion The novel arcuate multi-channel rectal endoluminal applicator can significantly reduce rectal wall pressure and deformation,while also reducing the dose to OAR without compromising target dose coverage,offering certain therapeutic advantages.

关 键 词：直肠肿瘤 近距离放射疗法 施源器 多通道 适形设计 

分 类 号：R735.37[医药卫生—肿瘤] R445.2[医药卫生—临床医学]