Oncentra近距离计划系统和MIM系统间DVH参数差异的分析

目的对近距离治疗计划的剂量参数在Oncentra治疗计划系统与MIM系统间产生的差异进行分析和研究。方法选取本院的43例妇科肿瘤患者近距离治疗计划,按照临床要求所有病例的靶区D₉₀达到处方剂量。评估参数包括:靶区体积和D₉₀,处方剂量总体积,靶区内的处方剂量体积以及危及器官包括:直肠,膀胱,小肠的D_0.01cc,D_1cc,D_2cc。结果计划系统中的靶区体积和处方剂量值均明显小于MIM系统中相应的值(P<0.05),两系统显示出的处方体积相差不大。MIM系统中的靶区D₉₀(676.74±54.82)cGy小于处方剂量,危及器官的受量则正好相反,即计划系统比MIM系统中相应的参数要小,其中直肠和膀胱的D_0.01cc,D_1cc,D_2c,小肠的D_0.01cc,D_2cc的在两系统显示的值的差异均有统计学意义(P<0.05)。结论不同系统间传输相同的剂量和轮廓文件,DVH参数存在一定的差异,其主要原因是在不同系统对已勾画的各种器官轮廓计算体积存在算法上的不同。基于此,建议近距离计划在CT扫描时,尽量小的层厚可以消除或减少这种差异。     

CT引导下三管式腔内后装与腔内结合插植后装用于宫颈癌治疗的对比研究

目的:比较局部晚期宫颈癌采用标准三管施源器的腔内后装(tandem and ovoid)与腔内结合组织间插植后装的剂量学差异。方法:CT引导下的三维适形近距离治疗局部晚期宫颈癌患者20 例，间隔采用三管式腔内后装与腔内结合组织间插植共 72次。 按照施源器的不同分成 ２个组，每组 36 次，对靶区剂量、危及器官等进行比较。结果:在给予A点相同处方剂量的情况下，HR-CTV D90、D100在三管式腔内后装组与腔内结合组织间插植后装组中分别为（590.0±46.4）cGy、（471.2±66.2）cGy，（502.8±67.7）cGy、（335.9±46.0）cGy，P＜0．05)，膀胱、直肠、乙状结肠D2cc均相近（P=0.85、0.28、0.53）。结论:采用腔内结合插植后装治疗局部晚期宫颈癌比三管式腔内后装可获得更高的靶区剂量，但长期疗效及晚期反应仍需进一步研究。     

CT引导徒手腔内联合插植自适应后装与传统A点后装治疗宫颈癌剂量比较

目的 探讨CT引导徒手腔内联合插植实现影像引导自适应后装(IGABT)相较于传统A点二维后装(CP)剂量学优势,明确其在宫颈癌治疗中的价值。方法 选取在中山大学肿瘤医院行全量放疗的宫颈癌患者 26例,每例患者行4次后装治疗。治疗时先徒手置入宫腔管及2根插植针,后增加插植针数量并调整方向、深度,分别行CT扫描获得2套图像。勾画高危临床靶区(HRCTV),A点和危及器官(直肠、膀胱及乙状结肠)。在2套图像上分别行CP和IGABT计划设计,并配对t检验、Wilcoxon检验两者剂量参数差异。结果 以CP计划的覆盖指数(CI)进行分组,A组(CI≥0.90)包含20个CP和对应IGABT计划,B组(CI<0.90)包含84个CP和对应IGABT计划。A组的HRCTV体积及肿瘤直径明显小于B组(46.7cm³∶62.1cm³,P<0.001及3.1cm∶4.4cm,P<0.0001)。IGABT显著提高所有及B组D90%及覆盖指数,降低膀胱剂量,减少A组乙状结肠剂量,并改善剂量适形度及均匀性。结论 IGABT能提高靶区覆盖、剂量适形度和均匀性,保护危及器官,且对肿瘤较大的患者仍有优势。     

Evaluating the Incidence Rate of an Accelerated Short Course High Dose Rate Intravaginal Brachytherapy Complications in Patients with Endometrial Cancer

Background: Brachytherapy in treatment of endometrial cancer patients is growing and therefore, evaluation ofmore feasible schedule has become of great importance. The purpose of current study was to evaluate the complicationsof accelerated short course high dose rate intravaginal brachytherapy (HDR IVB), a new brachytherapy approachwhich is a more feasible treatment option in developing countries. Method: From 2017 to 2018, 54 patients diagnosedwith endometrial cancer and FIGO stages IA to IIB who underwent total abdominal hysterectomy with a bilateralsalpingo-oophorectomy were enrolled in present study. They were treated with a total dose of 25 Gy in 5 fractionswhich was prescribed daily. A dose of 5 Gy was prescribed at a depth of 0.5 cm in the upper third and middle thirdof vagina. Adverse effects related to organs at risk consist of bladder, vagina and rectum were documented based onthe Common Terminology Criteria for Adverse Events v3.0 (CTCAE v3.0). Results: The accelerated short courseHDR IVB was well tolerated and no grade 3 or higher toxicities was reported for patients during the follow up period.There were no chronic rectal toxicities and only one patient showed chronic urinary toxicities. However, the incidencerate of vaginal toxicities at the end of 4-month and 8-month follow up periods was higher than acute toxicities andsignificantly lower in elderly group compared to younger group. Conclusion: Overall, the accelerated HDR IVB wassafe and was well tolerated in endometrial cancer patients and the incidence rate of undue complications were equal,if not less, in elderly patients compared to the younger ones.     

ICRU89号报告解析之临床篇——宫颈癌自适应近距离放疗靶区勾画

宫颈癌根治性放疗中,近距离放疗发挥了非常重要的作用。宫颈癌近距离放疗ICRU89号报告,在三维近距离治疗基础上引入时间的概念,正式提出自适应(4D)近距离放疗。本文在ICRU89号报告的基础上查阅相关资料,结合本中心经验,针对文中靶区勾画相关章节进行分析、归纳、总结,希望能帮助同行理解和掌握。     

伴区域淋巴结或合并远处转移的放射性碘难治性分化型甲状腺癌125I粒子植入治疗的疗效及安全性

目的:评估125I粒子植入治疗放射性碘难治性分化型甲状腺癌（RAIR-DTC）伴区域淋巴结或远处转移瘤的有效性及安全性，并分析患者肿瘤大小、肿瘤相关标志物Tg值的变化，以及短期疗效与肿瘤体积大小、增强扫描强化程度的相关性。方法:回顾性分析2015年5月至2018年7月42例经由病理与影像证实的RAIR-DTC伴淋巴结或合并远处转移的住院患者，均行CT引导下125I粒子植入治疗。患者术前行CT增强扫描及计算强化程度，并利用计算机三维治疗计划系统（TPS）测量肿瘤体积。术后2、6、12个月参照实体瘤治疗疗效评价标准(RECIST 1.1 标准)联合骨转移瘤MDA疗效评价标准评价治疗效果。结果:42例患者手术顺利，术后2、6、12个月的局部缓解率分别为97.62%（41/42）、88.10%(37/42)、85.71%(36/42)。其中3例声嘶、4例咳嗽的患者症状均较前明显缓解，8例患者术后NRS疼痛评分(2.00±1.07)较术前(4.88±0.83)明显下降（P＜0.001）。治疗后2、6、12个月复查病灶体积分别为（4.44±1.57)cm3、(4.20±1.70)cm3、(4.23±1.77)cm3，均较术前基线水平(6.87±1.67)cm3明显减小(t值:9.466、9.923、7.556，均P＜0.05)。治疗后2、6、12个月复查Tg值水平分别为15.95(5.45,73.93) μg/L、8.90(2.20,39.21)μg/L、6.00(1.93,14.18)μg/L，均较术前基线水平53.50(20.94,222.92)μg/L明显降低（Z值:-5.258、-5.009、-4.987,均P＜0.001）。肿瘤体积、CT强化程度是术后疗效的影响因素。结论:125I粒子组织间植入治疗RAIR-DTC伴区域淋巴结转移或合并远处转移的病灶局部控制效果较好、安全性高，具有较高的临床应用价值,且肿瘤体积小、强化程度高时疗效明显。     

Clinical feasibility of MR-assisted CT-based cervical brachytherapy using MR-to-CT deformable image registration

PurposeThe purpose of this study is to evaluate the feasibility of using deformable image registration algorithms to improve high-dose-rate high-risk clinical target volume (HR-CTV) delineation between preapplicator implantation MRI (pre-MRI) and postapplicator implantation CT (post-CT) in the treatment of locally advanced cervical cancer (LACC).Method and materialsTwenty-six patients were identified for the study. Regions of interest were segmented on MRI and CT. A HR-CTV was delineated on pre-MRI and compared with the previously contoured HR-CTV on the post-CT. Two commercially available algorithms, ANACONDA (anatomically constrained) and MORFEUS (biomechanical model based) with various controlling structure settings, including the cervix, uterus, etc., were used to deform pre-MRI to post-CT. MRI-to-CT deformed targets are denoted as HR-CTV’. Quantitative deformation metrics include Dice index, distance to agreement, and center of mass displacement. Qualitative clinical usefulness of deformations was scored based on HR-CTV identification on CT images.ResultsFor ANACONDA and MORFEUS deformations, using a cervix controlling region of interest resulted in the highest Dice, lowest distance to agreement, and lowest center of mass displacement for HR-CTV′. With MORFEUS deformations, the deformed HR-CTV’ proved clinically useful in 23 patients.ConclusionsPrebrachytherapy implantation MRI can aid target contours for CT-based brachytherapy through ANACONDA or MORFEUS algorithms with appropriate parameter selection for LACC patients.