颈段食管癌IMRT与3D-CRT剂量比较

颈段食管癌在临床中少见,约占整个食管癌的5%~10%[1]。可手术的颈段食管癌由于复杂的解剖关系使颈段食管癌手术难度大,手术范围较广,甚或需切除喉等重要器官。

基于3DCRT、IMRT、VMAT三种放疗技术的宫颈癌剂量分布比较

目的:对比三维适形放疗(3DCRT)、不同射野数目调强适形放疗(IMRT)、容积弧形调强放疗(VMAT)三种不同放疗技术在宫颈癌根治术后计划靶体积(PTV)以及危及器官(OAR)保护方面的差异。方法:取宫颈癌根治术的60例患者,所有患者均拟行术后盆腔外照射治疗,分别制定4野3DCRT、5野7野9野IMRT、5野VMAT放疗计划,处方剂量为50Gy,对比不同放疗计划靶区分布均匀度以及适形度、危及器官受照体积等指标。结果:5F-IMRT、7F-IMRT、9F-IMRT PTV剂量分布均匀性明显优于3DCRT(P<0.05),但与VMAT比较无显著差异(P>0.05);不同放疗计划比较中7F-IMRT与9F-IMRT的适形度最理想,其次为5F-IMRT、VMAT、3DCRT;IMRT、VMAT高剂量区对直肠、膀胱、小肠的保护作用明显强于3DCRT,而VMAT在20Gy条件下对小肠的保护作用略次于7F-IMRT、9F-IMRT,但VMAT对直肠、膀胱的保护作用与IMRT比较无显著差异(P>0.05);VMAT在机器跳数、治疗时间中较IMRT、VMAT具有显著优势(P<0.05)。结论:在不同放疗技术的宫颈癌剂量分布中发现,VMAT、IMRT具有良好的适形度以及危及器官保护能力,并且PTV分布均匀度也较为理,同时VMAT还可有效减少机器跳数以及缩短治疗时间,可作为一种宫颈癌术后放疗的良好放疗技术。

胸上段食管癌3D-CRT与IMRT的剂量学比较

目的对胸上段食管癌3D-CRT与IMRT进行剂量学比较。方法选取2016年1月—2018年1月到我院进行治疗的22例胸上段食管癌患者作为研究对象。所有患者均在实际治疗中采用3D-CRT计划。同时,为患者设计IMRT计划进行对比。结果 IMRT与3D-CRT GTV mean(cGy)对比,差异无统计学意义(P>0.05);CTV Dmean、两肺受照射平均剂量(cGy)、V30、V20,心脏V40、V30,脊髓Dmax(cGy)等指标,IMRT均低于3DCRT,差异具有统计学意义(P<0.05)。双肺V10对比,差异无统计学意义(P>0.05);双肺V5对比,IMRT高于3D-CRT,差异具有统计学意义(P<0.05)。结论 IMRT在胸上段食管癌治疗中具有更好的剂量适形性。

Dosimetric Comparison between Three Dimensional Conformal Radiation Therapy (3DCRT) &Intensity Modulated Radiation Therapy (IMRT) in Mid-Lower Oesophageal Carcinoma

Purpose: To investigate if intensity modulated radiation therapy (IMRT) offers a better planning target volume (PTV) coverage and/or lower dose to normal thoracic structures in comparison to three dimensional conformal radiation therapy (3DCRT) in the treatment of mid and lower oesophageal carcinoma patients. Materials and Methods: A prospective study in the period from 2014 till 2015 was held in the radiation therapy department of the National Cancer Institute, Cairo University, in which 20 locally advanced or inoperable mid and lower oesophageal cancer patients were treated by chemo-radiation using 3DCRT technique. IMRT plans were generated for those 20 patients. The 3DCRT and IMRT plans were compared as regards PTV coverage and doses to critical organs at risk. Results: All plans had produced satisfactory PTV coverage with no significant differences noted. The lung V20 for both lungs in 3DCRT was 16.94% ± 4.2% which was increased to 21.42% ± 3.6% in IMRT (p = 0.017). The mean dose to the heart and V30 were higher in IMRT plans while the mean dose to the spinal cord was higher with 3DCRT plans, yet that didn’t reach a statistically significant level (p = 0.156). The dose delivered to the liver didn’t pose any difference between both techniques. Conclusion: 3DCRT remains to be a feasible cost effective treatment delivery option for mid and lower oesophageal cancer cases with a lower optimization and delivery time than that for IMRT. Moreover, that calls for further dosimetric studies and clinical trials to assess IMRT technique. In our study, IMRT using nine fields didn’t prove to be superior to 3DCRT.

Evaluation of 3-D Printed Immobilisation Shells for Head and Neck IMRT

This paper presents the preclinical evaluation of a novel immobilization system for patients undergoing external beam radiation treatment of head and neck tumors. An immobilization mask is manufactured directly from a 3-D model, built using the CT data routinely acquired for treatment planning so there is no need to take plaster of Paris moulds. Research suggests that many patients find the mould room visit distressing and so rapid prototyping could potentially improve the overall patient experience. Evaluation of a computer model of the immobilization system using an anthropomorphic phantom shows that >99% of vertices are within a tolerance of ±0.2 mm. Hausdorff distance was used to analyze CT slices obtained by rescanning the phantom with a printed mask in position. These results show that for >80% of the slices the median “worse-case” tolerance is approximately 4 mm. These measurements suggest that printed masks can achieve similar levels of immobilization to those of systems currently in clinical use.

颈段及胸上段食管癌IMRT与3DCRT剂量比较

颈段及胸上段食管癌在临床中较为少见，由于其生物学特性及复杂的解剖关系使颈段食管癌手术难度大，手术治疗时切除范围较广，甚或需切除喉等重要器官，而仅有少数患者通过手术治愈。

用替吉奥化疗术联合3-DCRT治疗中晚期食管胃结合部肿瘤的效果分析

目的:探讨用替吉奥化疗术联合3-DCRT(三维适形放疗术)治疗中晚期食管胃结合部肿瘤(CEG)的临床效果。方法:对2010年3月~2014年3月期间我院收治的60例中晚期食管胃结合部肿瘤患者的临床资料进行回顾性研究。我们将这60例患者随机分为观察组和对照组,每组各有30例患者。我院使用3-DCRT对对照组患者进行治疗,联合使用替吉奥化疗术和3-DCRT(方法与对照组患者相同)对观察组患者进行治疗。治疗结束后,比较两组患者治疗1天后和治疗8天后KPS(Karnofsky功能状态)的评分情况、1年生存率、2年生存率、3年生存率及发生不良反应的情况。结果:观察组患者治疗1天后和治疗8天后KPS的评分均明显高于对照组患者,二者相比差异具有显著性(P<0.05)。两组患者的1年生存率相比无显著性差异(P>0.05)。但观察组患者的2年生存率和3年生存率均明显高于对照组患者,二者相比差异具有显著性(P<0.05)。在治疗期间,两组患者发生不良反应的几率大体相当,二者相比差异无显著性差异(P>0.05)。结论:用替吉奥化疗术联合3-DCRT治疗中晚期食管胃结合部肿瘤效果显著,可有效地提高患者的生活质量,延长其生存时间,而且安全性较高。此疗法值得在临床上推广使用。

Radiotherapy to the Left Breast with 3DCRT, IMRT or VMAT: International Medical Center Experience

Radiation therapy after conservative breast surgery is an integral part of the treatment of early breast cancer. The aim of radiotherapy is to achieve the best coverage of the Planning Target Volume (PTV), while reducing the dose to the Organs at Risk (OAR). Such goals are not always achievable with the conformal three dimensions plans (3DCRT). Recently, radiation oncologist uses Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for irradiating the breast. In this study, we compared 3DCRT, IMRT and VMAT for left breast cancer patients in terms of PTV coverage, OAR. We also revised the different dose distribution in 1) different breast volume categories, 2) nodal irradiation versus breast only, and 3) boost versus no boost. Results: The routinely reported dose constrains for the ipsilateral lung and for the heart were not significantly different on comparing the three techniques. While for the contralateral lung, the difference in mean dose was in favor of 3DCRT. In large breast volume, 3DCRT provided a lower Max dose to the contralateral lung and the lowest mean dose to the contralateral breast when compared to IMRT p < 0. 046. In case of no nodal irradiation, the contralateral breast mean dose was lower in 3DCRT in comparison to IMRT and VMAT p < 0.037. When boost dose was given, 3DCRT plans had produced a lower Max dose to the contralateral lung p < 0.017. Conclusion: The three techniques (3DCRT, IMRT, and VMAT) can meet the clinical dosimetry demands of radiotherapy for left breast cancer after conservative surgery, as long as the routinely OARs only (heart and ipsilateral lung) are reported. Our study showed that 3CDRT can provide a lower dose to the contralateral organs (breast and lung), specially, in case of large breast volumes, no nodal irradiation and when a boost is given.

IMRT对新疆大鼠继发性骨棘球蚴杀灭效果的实验研究

目的观察三维适形调强放疗(IMRT)对新疆大鼠继发性骨棘球蚴的杀灭效果,探讨IMRT对骨棘球蚴病的治疗有效性。方法选取股骨继发性棘球蚴病大鼠50只,对50只大鼠左侧股骨棘球蚴病区给予剂量40Gy的IMRT放疗,于放疗1w后活杀取材,取大鼠左、右股骨棘球蚴包囊后行电镜观察,应用RT-PCR法定量检测骨棘球蚴包囊中凋亡相关基因Caspase-3的表达情况。结果 IMRT作用1w后,电镜下均可观察到接受IMRT治疗的大鼠左侧股骨的骨棘球蚴包囊存在明显的放射损伤,而右侧未出现;RT-PCR法检测发现接受IMRT治疗的大鼠左侧股骨的骨棘球蚴包囊的细胞中凋亡相关基因Caspase-3大量表达,RQ值为(67.39±17.35),而右侧则极少量表达,RQ值为(1.43±0.53),差异有统计学意义(P<0.05)。结论 IMRT可促进新疆大鼠继发性骨棘球蚴包囊细胞的凋亡,其作用机制可能是通过调节凋亡相关蛋白Caspase-3而实现的。

胃癌术后IMRT与常规对穿及适形照射剂量学的比较

目的比较胃癌术后常规放射治疗与适形及调强(IMRT)治疗技术在同一处方剂量(45 Gy)时的剂量分布特点,为临床提供参考。方法选取9例胃癌术后患者,在CT图像序列上勾画出临床靶区(CTV),CTV外放1 cm定义为计划靶区PTV,对PTV分别用常规两野对穿、适形5野及5野调强照射技术进行计划设计。所有方案处方剂量均为45 Gy,要求95%体积PTV接受45 Gy剂量,IMRT与适形计划采用优化以保证≥95%的PTV接受45 Gy的处方剂量,99%的PTV接受42.75 Gy。根据剂量体积直方图(DVH)比较PTV受量和正常器官的受量差异和剂量分布,并计算正常组织并发症概率(NTCP)。结果IMRT能够产生优于常规及适形的靶区剂量分布,均匀性及适形度明显优于常规对穿照射。IMRT的左肾受23 Gy剂量的体积百分比(V23)明显低于常规及适形技术,从脊髓剂量来看,IMRT的脊髓最大剂量为(39.3+2.3),小于40 Gy,明显优于常规前后对穿及适形照射技术,并相应减少脊髓的NTCP值。结论IMRT相对于常规对穿照射及适形照射具有明显的靶区剂量分布优势,可以减少肾脏、脊髓等正常组织器官的照射体积百分比及NTCP值。

老年胰腺癌3种放射治疗的疗效对比

胰腺癌的5年生存率仅为5％，是预后极差的恶性肿瘤之一〔1，2〕。老年胰腺癌患者体质较差治疗局限性较多，传统疗法多不适用。以往认为该病是对放疗抗拒的肿瘤，而且由于胰腺周围存在放射耐受性差的正常组织（肝脏、肾脏、脊髓、胃等），并不选择放疗。但随着放疗设备的不断改进及精确放疗技术的飞速发展，放疗已成为胰腺癌的主要治疗手段之一〔3〕。对于老年胰腺癌患者，治疗肿瘤的同时，最大限度减轻不良反应尤为重要。三维适形放疗（3DCRT）、静态调强放射治疗（IMRT）等技术已普及。容积旋转调强治疗（ VMAT ）是近年来发展起来的高尖端放疗技术，已在各种肿瘤治疗上获得了良好的效益〔4〕，但国内尚无其在胰腺癌治疗上应用的报道。本文拟比较3DCRT、IMRT、VMAT 3种治疗计划对老年胰腺癌患者的效果。

犬脊柱IMRT和普通放疗对脊髓神经元凋亡的影响

目的:通过比较脊柱适形调强放疗(IMRT)和普通放疗对犬脊髓神经元凋亡的影响,证明脊柱IMRT的生物安全性。方法:选取纯种比格犬16只并随机分为IMRT组和普通放疗组,模拟犬胸9～10椎体肿瘤,以IM-RT和普通放疗2种方式分别对2组比格犬胸9～10椎体给予50、70Gy剂量的放疗,于放疗3个月后活杀取材,取相同部位、相同位置的胸9～10节段脊髓材料行HE染色、电镜观察后,免疫组织化学法定量检测脊髓中凋亡蛋白半胱氨酸蛋白酶-3(Caspase-3)的表达,末端脱氧核苷酸转移酶介导的脱氧尿嘧啶缺口末端标记(TUNEL)法定量检测脊髓中凋亡神经元。结果:照射3个月后可观察到脊髓损伤,IMRT组脊髓神经元以可逆性损伤为主,而普通放疗组以凋亡为主。相同剂量的放疗,IMRT组细胞凋亡指数[放疗剂量为50、70Gy时分别为(1.2±0.7)%、(2.5±0.8)%]均低于普通放疗[放疗剂量为50、70Gy时分别为(7.3±1.1)%、(11.3±1.4)%];凋亡蛋白Caspase-3表达量IMRT组[放疗剂量为50、70Gy时分别为(3.2±0.6)、(5.1±1.0)]明显低于普通放疗组[放疗剂量为50、70Gy时分别为(13.6±3.1)、(18.9±2.4)]。结论:照射3个月后脊髓中存在着明显的放疗迟发反应。通过放疗后脊髓神经元形态学、神经元凋亡指数、凋亡蛋白Caspase-3表达等指标的测定结果提示脊柱IMRT的脊髓安全性远优于普通放疗。

Mapcheck 3的剂量学特性测量及比较

目的SNC于2018年底推出了新一代的Mapcheck,并命名为Mapcheck 3。测量Mapcheck2和3的剂量学特性,分析Mapcheck 3的剂量学特性曲线,并和Mapcheck 2进行比较。探讨新一代的Mapcheck能否满足临床需求以及改进。方法分别测量新旧两代Mapcheck的探头一致性、剂量线性和测量重复性。结果归一后Mapcheck 3的探头一致性为0.0154%;剂量线性为0.0394%;测量重复性为0.0121%;剂量线性结果经过直线回归后常数项为-0.09232;回归系数为1.054107。结论Mapcheck 3中的新一代探测器的剂量学特性满足临床使用要求,并且因为体积更小能够在调强验证中提供更高的空间分辨力。

Comparative Study of Dose Distribution Homogeneity between 3D-Brachytherapy and Intensity Modulated Radiation Therapy Techniques in Cervix Cancer Tumors

Aim: The purpose of this study was to compare the dosimetric results of the techniques (3D-Brachytherapy and intensity-modulated radiotherapy IMRT) in patients with locally advanced cervical carcinoma (LACC). Method: There are 15 patients with locally advanced cervical carcinoma (LACC), after the completion of external beam radiotherapy (EBRT) for the whole pelvic irradiation 45 Gy/25 fractions, followed by 3D-Brachytherapy 24 Gy per weekly fractions and 36 Gy of IMRT per 18 fractions. Coverage of targets volume and doses received by normal tissue were compared in two techniques. Method: 15 patients of LACC treated with 3D-Brachytherapy were selected for this study. IMRT plans were also created for all the patients. 3D-Brachytherapy and IMRT plans were compared on the basis of target volume coverage, dose to Organs at risk (OAR’s), homogeneity index (HI) and conformity index (CI). Results: The results showed that D90% of HRCTV in the 3D-Brachytherapy was covered more than D90% of PTV in the IMRT of prescribed dose, the D2CC and the V60Gy values of Bladder and rectum were significantly lower than in 3D-Brachytherapy. The HI and CI in 3D-Brachytherapy were found better than IMRT. Conclusion: 3D-Brachytherapy significantly reduced the irradiated volume of OAR’s and improved dose coverage in tumor volume compared to that by IMRT.

The Effect of Treatment Position on Rectal and Bladder Dose-Volume Histograms for Prostate Radiotherapy Planned with 3-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy

Purpose: To compare target coverage and organ at risk (OAR) sparing in the supine and prone positions with 3-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) in low- and high-risk prostate radiotherapy cases. Materials and Methods: Using magnetic resonance images of five healthy volunteers, six treatment plans (supine 3DCRT, prone 3DCRT, supine IMRT, prone IMRT, supine VMAT and prone VMAT) were generated. Planning target volume 1 (PTV1) was defined as the prostate gland plus the seminal vesicles with adequate margins in a high-risk setting, while PTV2 was defined as prostate only with margins in a low-risk setting. The mean dose for both PTV1 and PTV2 was set at 78 Gy. Plans generated by each of the 3 techniques were compared between the supine and prone positions using dose-volume histograms (DVHs). Results: For PTV1, prone 3DCRT provided a significantly higher D98% than did supine 3DCRT, and its homogeneity index (HI) was significantly better. IMRT and VMAT values did not differ significantly between the prone and supine positions. For PTV2, no values differed significantly between the supine and prone positions under any treatment plan. With respect to OAR, the rectal D mean, D2%, V50, and V60 values of PTV1 were statistically higher in supine 3DCRT than in prone 3DCRT, while there were no significant differences in rectal values between the supine and prone positions with IMRT or VMAT. The rectal Dmean, V50, V60, V70, and V75 values of prone 3DCRT were significantly higher than those of supine IMRT or supine VMAT. There were no significant differences in any values for the rectum and bladder for PTV2. Conclusion: Although prone 3DCRT was found to be superior to supine 3DCRT in terms of rectal sparing in high-risk prostate cancer, IMRT and VMAT techniques could possibly cover this disadvantage.

Dosimetric Comparison: Volumetric Modulated Arc Therapy (VMAT) and 3D Conformal Radiotherapy (3D-CRT) in High Grade Glioma Cancer—Experience of Casablanca Cancer Center at the Cheikh Khalifa International University Hospital

Background: Intensity Modulated Radiation Therapy (IMRT) is currently employed as a major arm of treatment in multiforme glioblastoma (GBM). The present study aimed to compare 3D-CRT with IMRT to assess tumor volume coverage and OAR sparing for the treatment of malignant gliomas. Materials and methods: We assessed 22 anonymized patients datasets with High Grade Glioblastoma who had undergone post-operative Intensity Modulated Radiotherapy (IMRT) and 3D Conformal Radiotherapy (3D-CRT), This study will compare and contrast treatment plans Rapidarc and 3D-CRT to determine which technology improves significantly dosimetric parameters. Results: Plans will be assessed by reviewing the coverage of the PTV using mean, maximum and minimum doses while the OAR doses will be compared using the maximal doses for each, as set out in the QUANTEC dose limits. Conclusion: The use of IMRT seems a superior technique as compared to 3D-CRT for the treatment of malignant gliomas having the potential to increase the dose to the PTV while sparing OARs optimally.

3野和5野调强放疗计划治疗胸段食管癌的剂量学差异

目的:比较胸段食管癌3野和5野调强放疗计划治疗的靶区和相关危及器官的剂量学差异。方法;回顾性分析泉州市光前医院2019年9月至2020年8月收治的胸段食管癌患者281例,根据治疗方案不同分为两组,3野组146例和5野组135例,3野组给予3野调强计划,5野组给予5野调强计划,比较两种治疗计划的靶区和危及器官的剂量学差异。结果:在计划靶区(PTV)1、PTV2上,两种调强放疗的D_(max)、D_(min)、D_(mean)上的差异均无统计学意义(P>0.05),5野调强放疗的D_(95)、V_(95%)与CI高于3野调强放疗,HI低于3野调强放疗,差异均具有统计学意义(P<0.05);5野调强放疗的左右肺V_(5)、V_(20)、V_(30)高于3野调强放疗,差异均具有统计学意义(P<0.05)。结论:5野调强放疗计划的靶区适形度远高于3野调强放疗计划,在大多数患者的应用中具有一定优势。

脑胶质瘤三维适形放射治疗与调强放射治疗的剂量学比较

探讨脑胶质瘤调强放疗技术(IMRT)比三维适形放疗技术(3D-CRT)在剂量上的优越性。方法 选取20名胶质瘤病人,分别设计3D-CRT计划和IMRT计划,采用剂量体积直方图(DVH)评估不同照射技术下的照射剂量、适形度指数及非均匀度指数。处方:总剂量60Gy,单次剂量为2Gy,30次。结果 与3D-CRT方案相比,IMRT方案的最大亮点在于脑干的照射体积、脊髓的最大剂量、患侧腮腺平均剂量等较3D-CRT方案低。同时在靶区适形指数方面,IMRT计划要好于3D-CRT计划;在非均匀度指数上,两种计划在统计上无显著差别。结论 对于脑胶质瘤的放射治疗,采用IMRT技术,相比3D-CRT计划,在靶区适形性上优势显著,同时对危及器官的保护方面也有明显剂量学优势。这为增加靶区的照射剂量提供了可能。

保乳术后乳腺癌三维适形或调强放疗早期毒副反应分析

目的:分析乳腺癌保乳术后三维适形放疗(3DCRT)或调强放射治疗(IMRT)早期放射性皮炎和肺炎的发生率及相关的临床与剂量学因素。方法:回顾分析81例保乳术后乳腺癌,3DCRT治疗32例,IMRT治疗49例。单纯全乳腺放疗56例,乳腺联合锁上照射25例,均未照射腋窝或内乳。乳腺联合锁上剂量5 0 Gy/2 5次,瘤床补量1 5 Gy/5次。单纯放疗1 6例,其余均为放化综合治疗。结果:Ⅰ度皮肤反应35例(43.2%),Ⅱ度44例(54.3%),Ⅲ度仅2例(2.5%)。3DCRT组25例(78.1%)发生Ⅱ-Ⅲ度急性皮肤反应,高于IMRT组21例(42.9%),P=0.002。56例锁上未放疗者,24例Ⅰ度反应和32例Ⅱ-Ⅲ度反应的临床靶区(CTV)体积均数分别为543.21 cm3和688.81cm3,P=0.005。放化疗顺序对皮肤反应没有影响。有临床症状的I度放射性肺炎7例(8.6%),Ⅱ度和Ⅲ度各1例。IMRT组Ⅰ度5例,Ⅱ-Ⅲ度2例;3DCRT组I度2例,无Ⅱ度及以上放射性肺炎发生。两组比较差异未见统计学意义。剂量体积因素及临床因素如年龄、化疗、内分泌治疗等对放射性肺炎无影响。结论:无论IMRT还是3DCRT,严重的急性皮肤反应均较低,但是IMRT较3DCRT能更好的保护乳腺皮肤;乳腺体积大者皮肤反应发生率高。本研究中有症状的肺炎发生率低,未发现与放射性肺炎相关的临床和剂量学因素。