3DVH系统在鼻咽癌容积旋转调强剂量验证中的应用研究

目的：研究3DVH系统在鼻咽癌容积旋转调强计划剂量验证中的应用。方法：选取18例鼻咽癌病例在Pinnacle计划系统（9.2版本）中进行容积旋转治疗计划设计,通过网络把治疗计划传输至MOSAIQ网络系统上,同时把治疗计划导入ARCCHECK模体重新进行剂量计算。然后把重新剂量计算得到的剂量和计划文件以DICOM的格式传输到3DVH软件系统中,比较靶区和危及器官的理论计算和实际测量之间的差异。其中比较的参数主要有：靶区的平均量（Dmean）、2%体积剂量（D2%）、98%体积剂量（D98%）以及Y通过率。危及器官如脊髓、脑干、视神经、眼晶体以及视交叉的平均剂量（Dmean）、1%体积剂量（D1%）。腮腺的平均剂量（Dmean）、30Gy的剂量体积（V30Gy）以及50%体积剂量（D50%）。结果：各个靶区的γ通过率均在95%以上,Dmean和D2%差异在1%以内,D98%差异在1.5%以内。危及器官的理论和实际测量的差异大都在1.5%以内。结论：3DVH系统是一种方便快捷的鼻咽癌容积旋转调强剂量工具,它可以更加直观的显示计划系统理论计算结果和实际测量结果之间的差异。     

COMPASS系统在直肠癌术前调强放射治疗三维剂量验证中的应用

目的探讨COMPASS系统在直肠癌术前调强放射治疗三维剂量验证中的应用价值。方法选取2018年8月至2019年3月福建医科大学附属漳州市医院收治的直肠癌患者21例作为研究对象,调强放射治疗前用COMPASS系统提供的剂量计算(CDD)、剂量重建(RDD)两种方法验证计划靶区γ通过率及剂量体积偏差。结果γ通过率:靶区与危及器官剂量计算-治疗计划系统(CDD-TPS)的γ通过率均>98.0%,明显高于剂量重建-治疗计划系统(RDD-TPS),且两种方法验证的计划靶区γ通过率比较,差异有统计学意义(P<0.05)。剂量体积偏差:两种方法验证的计划靶区D2%、膀胱与右侧股骨头Dmean剂量偏差比较,差异有统计学意义(P<0.05)。结论 COMPASS系统可科学评估直肠癌术前调强放射治疗的治疗剂量。     

胸段食管癌累及野放疗与扩大野放疗对危及器官的辐射剂量学分析

目的 研究胸段食管癌逆向调强放射治疗（IMRT）中累及野照射与扩大野照射对危及器官（OAR）受照剂量的影响。方法 40例胸段食管癌患者分别行累及野靶区勾画和扩大野靶区勾画并勾画危及器官,制定IMRT计划,评估2个计划的靶区适形指数（CI）和均匀性指数（HI）及危及器官的剂量学参数,剂量学参数比较采用配对t检验。结果 2种计划的PTV均能满足处方剂量要求,PTV在CI、HI上相近（P=0.317、0.130）。两组间平均肺剂量、两肺V5、两肺V20、两肺V30、脊髓Dmean、心脏Dmean、心脏Dmax、心脏V30、心脏V40、心脏V60差异均存在统计学意义（P <0.01）。结论 胸段食管癌患者行累及野照射与扩大野比较,可降低正常器官的受照剂量,从而降低放射性损伤风险。     

左乳癌保乳术后4种放疗计划的剂量学比较

目的 比较左侧乳腺癌保乳术后行全乳放射治疗时4种放射治疗计划的靶区及危机器官剂量学差异,探讨保乳术后较优的放疗治疗方式。方法 随机选取23例左侧乳腺癌术后行全乳放射放疗患者,给予PTV 25分·次、50 Gy处方剂量;分别设计适形混合调强计划（Hybrid_IMRT）、限制铅门多野调强计划（restricted jaw,rj_IMRT）、双弧容积旋转调强计划（VMAT）和基于切线双弧容积旋转调强计划（tangent-based VMAT,t_VMAT）4种放疗计划。比较这4种计划的剂量学差异,包括靶区及危及器官OAR的剂量-体积直方图DVH,靶区均匀性指数HI和适形性指数CI以及机器跳数MU。结果 4种计划比较,靶区HI：t_VMAT最大,且与其余3种计划相比有差异统计学意义（均P < 0.001);靶区CI：VMAT的CI最大,0.967 ±0.016,与其它3者相比,差异有统计学意义（均P < 0.05）。rj_IMRT的CI为0.942 ±0.018,优于Hybrid_IMRT和t_VMAT。危及器官方面：左肺平均剂量,rj_IMRT为（8.76 ±1.52） Gy,优于其他3种计划,且差异有统计学意义（均P < 0.05）。心脏平均剂量：rj_IMRT为（4.68 ±0.87） Gy,优于VMAT的（6.90 ±1.27） Gy,且有统计学意义（P < 0.05）。结论 4种计划方式均可应用于临床治疗,计划制定者应考虑治疗设备限制、患者身体状况等因素选择合适的治疗计划。     

简易调强计划设计方法在上段食管癌调强计划临床应，的可行性研究

目的探讨一种简易调强计划设计方法在上段食管癌中的应用。方法选取6例胸上段食管癌患者,分别制定传统9野调强计划和简易调强计划,统一处方剂量60Gy／30F,比较靶区、危及器官的剂量体积参数,加速器的总机器跳数（MU）。结果传统9野调强计划与简易调强计划的靶区剂量分布基本一致。对于高剂量区1％体积的脊髓受量和双肺20Gy和30Gy照射的肺体积百分比（V20,V30）,两种计划的结果无明显差异（P〉O．05）,但简易调强设计方法可以减少脊髓、肺两种重要器官的低剂量受照体积,同时减少投射跳数（P〈0．05）。结论简易调强设计方法可以在胸上段食管癌中应用。     

基于OCTAVIUS 4D的全中枢容积旋转调强放疗的接野部位剂量验证研究

目的：研究使用OCTAVIUS 4D验证设备对全中枢容积旋转调强放疗计划进行接野部位剂量验证的可行性和准确性,为全中枢容积旋转调强放疗计划接野部位剂量验证提供参考方法。方法：选取12例接受全中枢容积旋转调强接野放疗的患者,在治疗计划系统中分别建立头部中心、胸部中心、腹部中心验证计划和头胸射野衔接处、胸腹射野衔接处验证计划,通过OCTAVIUS 4D验证设备采集真实剂量。通过前后移床验证相邻中心射野衔接处的剂量分布。使用Verisoft 7.1软件分析全中枢容积旋转调强放疗单中心验证计划和射野衔接处验证计划的γ通过率。结果：阈值为10%时,头部、胸部和腹部中心计划在3 mm/3%标准下的γ通过率分别为（99.68±0.60）%、（99.63±0.52）%和（99.53±0.86）%,高于美国医学物理学家协会（American Association of Physicists in Medicine,AAPM）报告的关于治疗前患者计划剂量验证通过率的建议。相同条件下不同相邻中心射野衔接处的剂量分布略有差异,头胸接野部位的γ通过率略低于胸腹接野部位的γ通过率,且差异具有统计学意义（P<...     

全脑+同步推量放射治疗中海马保护计划设计研究

目的:探讨应用Elekta Synergy医用直线加速器容积旋转调强放射治疗(VMAT),实现全脑+转移灶同步推量放射治疗的海马保护计划设计。方法:选取10例肺癌脑转移患者进行全脑放射治疗+转移灶同步推量,并进行海马保护。勾画转移灶肿瘤靶区(GTV)、全脑临床靶区(CTV)、左右海马区,以及脑干、脊髓、眼球、晶体等其他正常组织,转移灶外扩3 mm形成计划肿瘤靶区(PGTV),全脑外扩3 mm形成计划靶区(PTV),海马区外扩5 mm形成海马保护区域。利用Pinnacle9.8治疗计划系统设计VMAT计划,处方剂量PGTV为45 Gy/15 F,PTV为36 Gy/15 F。结果:10例患者PGTV的45 Gy覆盖为99.8%,均匀性指数平均值为0.09。PTV的36 Gy靶区覆盖80%,30 Gy靶区覆盖90.1%,左、右海马平均体积分别为3.2 cm^3和2.8 cm^3,海马保护区域平均体积分别为25.2 cm^3和23 cm^3。左、右海马的平均剂量为6.91 Gy和5.32 Gy,最大剂量分别为10.7 Gy和8.3 Gy;左、右海马保护区域的平均剂量为7.93 Gy和10.3 Gy,最大剂量为14.8 Gy和13.5 Gy。左右晶体最大剂量平均值分别为5.56 Gy和5.69 Gy。结论:在全脑放射治疗中,利用ElektaSynergy直线加速器VMAT技术能在保证靶区剂量覆盖和靶区适形性、均匀性的情况下降低海马受照剂量,达到安全剂量范围,可实现对患者海马神经认知功能的保护。     

宫颈癌术后调强放射治疗和三维适形放射治疗剂量对比

目的 研究宫颈癌术后调强放射治疗（IMRT）和三维适形放射治疗（3D-CRT）时靶区及其周围正常组织受照剂量的差异.方法 采用CMS公司的Xio 44放射治疗计划系统分别对12例宫颈癌术后患者进行3D-CRT和IMRT计划设计,95%PTV剂量50 Gy.利用剂量-体积直方图（DVH）计算靶区剂量适形指数（Cindex）和小肠、直肠、膀胱等正常器官受量以进行对比.计划执行采用Elekta公司的Precise电子直线加速器（6MV光子线）.结果 与3D-CRT相比,IMRT计划的直肠受到40 Gy、膀胱受到45 Gy、小肠受到50 Gy照射的体积所受剂量分别下降了375%、368%和91%,靶区的剂量适形指数提高了189%.同时,IMRT计划的直肠、膀胱平均剂量也显著低于3D-CRT计划.结论 宫颈癌术后IMRT剂量分布优于3D-CRT.     

CT/MRI诊断影像融合对非小细胞肺癌脑转移瘤靶区及三维适形治疗影响

目的：比较CT图像和CT/MRI融合图像来源的肺癌脑转移肿瘤靶区,评价CT/MRI融合靶区容积应用于三维适形放射治疗时,对治疗剂量的影响。方法：将20例非小细胞肺癌脑转移患者的增强CT和MRI扫描的图像传送至图像处理工作站,在CT和CT/MRI融合图像上分别勾画GTV和周围重要的器官。每个病例分别在CT图像和CT/MRI融合图像都做1个三维适形放射治疗计划。肿瘤的处方剂量为60 Gy,比较2个治疗计划中肿瘤靶区的95%容积（D95）受照平均剂量、周围正常组织的5%容积（D5）受照平均剂量。结果：CT/MRI融合图像上的肿瘤靶区平均比CT上的肿瘤靶区大21.32％。用CT上勾画的靶区有一部分肿瘤处于低剂量区,CT/MRI融合图像上的靶区D95剂量分布较好,但在周围重要器官的剂量分布较高。结论：CT/MRI融合图像有助于靶区的确定,在三维适形放射治疗计划上的肿瘤靶区剂量分布足够,能提高靶区勾画的准确性,更利于精确放疗的实施。     

运用ArcCHECK实施旋转调强全骨髓照射超长靶区的计划验证

探讨利用ArcCHECK对VMAT（Volumetric Modulated Arc Therapy）和HT (Helical Tomotherapy)全骨髓照射（TMI）超长靶区计划的验证方法。选取8例全身扫描患者,分别设计TMI计划。采用ArcCHECK对两组计划头颈、胸腹及盆腔三部位行验证分析。VMAT组采用模体Merge功能通过平移治疗床实现, HT组采用双计划（参考/执行）法得以完成,三部位验证通过率分别为98.9%±1.9%/94.3%±1.5%、98.4%±1.8%/96.5%±1.2%、97.4%±2.1%/94.1%±1.9%。表明利用ArcCHECK的Merge功能能较好地完成VMAT超长靶区的验证,采用双计划法实现了对HT超长靶区及远离中心部分靶区的验证。     

X线蒙特卡洛算法与有限元笔形束算法在旋转容积调强放疗计划中的剂量学比较

目的：比较Monaco治疗计划系统X线蒙特卡洛算法（X—ray voxel Monte Carlo,XVMC）和有限元笔形束算法（finite size pencil beam,FSPB）在食管癌和直肠癌旋转容积调强放疗计划中的剂量学差异。方法：选取7例食管癌和7例直肠癌旋转容积调强放疗计划,分别使用XVMC算法和FSPB算法进行剂量计算,比较靶区和危及器官的剂量分布差异。结果：XVMC算法的剂量计算值均高于FSPB算法,在食管癌的靶区和脊髓、直肠癌的靶区和危及器官,各项指标差值都小于3％,肺的各项指标差值最大达到10％。结论：在临床旋转容积调强治疗中,尤其是计算区域含有低密度组织较多的病例,优先推荐更为精确的XVMC算法进行剂量计算。     

Volumetric-modulated arc therapy for left-sided breast cancer and all regional nodes improves target volumes coverage and reduces treatment time and doses to the heart and left coronary artery,compared with a field-in-field technique

We compared two intensity-modulated radiotherapy techniques for left-sided breast treatment, involving lymph node irradiation including the internal mammary chain. Inverse planned arc-therapy (VMAT) was compared with a forward-planned multi-segment technique with a mono-isocenter (MONOISO). Ten files were planned per technique, delivering a 50-Gy dose to the breast and 46.95 Gy to nodes, within 25 fractions. Comparative endpoints were planning target volume (PTV) coverage, dose to surrounding structures, and treatment delivery time. PTV coverage, homogeneity and conformality were better for two arc VMAT plans; V95%^PTV-T was 96% for VMAT vs 89.2% for MONOISO. Homogeneity index (HI)^PTV-T was 0.1 and HI^PTV-N was 0.1 for VMAT vs 0.6 and 0.5 for MONOISO. Treatment delivery time was reduced by a factor of two using VMAT relative to MONOISO (84 s vs 180 s). High doses to organs at risk were reduced (V30^{left lung} = 14% using VMAT vs 24.4% with MONOISO; dose to 2% of the volume (D2%)^heart = 26.1 Gy vs 32 Gy), especially to the left coronary artery (LCA) (D2%^LCA = 34.4 Gy vs 40.3 Gy). However, VMAT delivered low doses to a larger volume, including contralateral organs (mean dose [Dmean]^{right lung} = 4 Gy and Dmean^{right breast} = 3.2 Gy). These were better protected using MONOISO plans (Dmean^{right lung} = 0.8 Gy and Dmean^{right breast} = 0.4 Gy). VMAT improved PTV coverage and dose homogeneity, but clinical benefits remain unclear. Decreased dose exposure to the LCA may be clinically relevant. VMAT could be used for complex treatments that are difficult with conventional techniques. Patient age should be considered because of uncertainties concerning secondary malignancies.     

Dosimetric and delivery characterizations of full-arc and half-arc volumetric-modulated arc therapy for maxillary cancer

We compared the efficiency and accuracy of full-arc and half-arc volumetric-modulated arc therapy (VMAT) delivery for maxillary cancer. Plans for gantry rotation angles of 360° and 180° (full-arc and half-arc VMAT) were created for six maxillary cancer cases with the Monaco treatment planning system, and delivered using an Elekta Synergy linear accelerator. Full-arc and half-arc VMAT were compared with regard to homogeneity index (HI), conformity index (CI), mean dose to normal brain, total monitor units (MU), delivery times, root mean square (r.m.s.) gantry accelerations (°/s(2)), and r.m.s. gantry angle errors (°). The half-arc VMAT plans achieved comparable HI and CI to the full-arc plans. Mean doses to the normal brain and brainstem with the half-arc VMAT plans were on average 16% and 17% lower than those with the full-arc VMAT plans. For other organs at risk (OARs), no significant DVH differences were observed between plans. Half-arc VMAT resulted in 11% less total MU and 20% shorter delivery time than the full-arc VMAT, while r.m.s. gantry acceleration and r.m.s. gantry angle error during half-arc VMAT delivery were 30% and 23% less than those during full-arc VMAT delivery, respectively. Furthermore, the half-arc VMAT plans were comparable with the full-arc plans regarding dose homogeneity and conformity in maxillary cancer, and provided a statistical decrease in mean dose to OAR, total MU, delivery time and gantry angle error. Half-arc VMAT plans may be a suitable treatment option in radiotherapy for maxillary cancer.     

Single-arc volumetric modulated arc therapy planning for left breast cancer and regional nodes

We have successfully created a single arc volumetric modulated arc therapy (VMAT) plan for treating post-surgical left breast/chest wall and regional nodes using Elekta multileaf collimator (MLC). Dose volume histograms (DVHs) were compared between the VMAT plans and conventional tangential beam plans using a field-in-field technique, leading to significant DVH advantages in the VMAT plans. The difference between Elekta VMAT and Varian RapidArc due to different MLC designs was discussed in terms of the number of arcs required to cover a large target, highlighting a single arc capability of Elekta VMAT for a large target volume which may be less sensitive to unexpected organ motion during dose delivery.     

鼻咽癌螺旋断层放疗与常规调强放疗能剂量学分析

目的比较鼻咽癌在螺旋断层放疗（Helical Tomotherapy）和常规调强放疗（IMRT）两种不同治疗系统中治疗计划的剂量学分布,并对靶区和危及器官的剂量进行分析。材料与方法选择18例鼻咽癌病例,将其定位数据信息及靶区器官轮廓分别传输至TomotherapyTPS工作站及Varian EclipseTPS工作站并设计调强放疗计划,18例患者的处方剂量相同,其中鼻咽部原发灶GTVnx为73．92Gy／33F;可见的转移淋巴结GTVnd为69．96Gy／33F;高危临床靶区CTV1为60．06Gy／33F;预防照射区CTV2为50．96Gy／28F,通过对靶区的适形度指数（CN）、均匀性指数（H1）和危及器官（OARs）的最大剂量及平均剂量等各项指标比较2组治疗计划,对两组数据进行配对f检验。结果螺旋断层放疗组中PGTVnx、PTV1、PTV2的CN值分别为0．910±0．010、0．855±0．020、0．871±0．021,常规调强组中PGTVnx、PTV1、PTV2的CN值分别为0．867±0．025、0．822±0．020、0．811±0．012,螺旋断层放疗组中PGTVnx、PTV1、PTV2的HJ值分别为1．049±0．009、I_135±0．030、1．034±0．011,常规调强组中PGTVnx、PTV1、PTV2的HI值分别为1．060±0．011、1．222±0：023、1．094±0．015,各组P值均〈0．005。螺旋断层放疗组相比常规调强放疗组各靶区的的均匀性指数和适形度指数均有不同程度的改善;危及器官的最大剂量和平均剂量也有所下降,腮腺平均剂量较常规调强放疗组低4Gv左右,V30、V35也显著低于常规调强放疗,P值〈0．005。结论对于鼻咽癌,螺旋断层放疗技术相对于常规凋强技术改善了剂量学分布,使得靶区在获得更好的剂量分布同时显著降低了正常组织的受照剂量。     

Whole-pelvic volumetric-modulated arc therapy for high-risk prostate cancer: treatment planning and acute toxicity

The objectives of this study were to evaluate dosimetric quality and acute toxicity of volumetric-modulated arc therapy (VMAT) and daily image guidance in high-risk prostate cancer patients. A total of 100 consecutive high-risk prostate cancer patients treated with definitive VMAT with prophylactic whole-pelvic radiotherapy (WPRT) were enrolled. All patients were treated with a double-arc VMAT plan delivering 52 Gy to the prostate planning target volume (PTV), while simultaneously delivering 46.8 Gy to the pelvic nodal PTV in 26 fractions, followed by a single-arc VMAT plan delivering 26 Gy to the prostate PTV in 13 fractions. Image-guided RT was performed with daily cone-beam computed tomography. Dose–volume parameters for the PTV and the organs at risk (OARs), total number of monitor units (MUs) and treatment time were evaluated. Acute toxicity was assessed using the Common Terminology Criteria for Adverse Events, version 4.0. All dosimetric parameters met the present plan acceptance criteria. Mean MU and treatment time were 471 and 146 s for double-arc VMAT, respectively, and were 520 and 76 s for single-arc VMAT, respectively. No Grade 3 or higher acute toxicity was reported. Acute Grade 2 proctitis, diarrhea, and genitourinary toxicity occurred in 12 patients (12%), 6 patients (6%) and 13 patients (13%), respectively. The present study demonstrated that VMAT for WPRT in prostate cancer results in favorable PTV coverage and OAR sparing with short treatment time and an acceptable rate of acute toxicity. These findings support the use of VMAT for delivering WPRT to high-risk prostate cancer patients.     

动态适形弧放射治疗与容积旋转调强放射治疗在非小细胞肺癌立体定向放射治疗中的剂量学差异

目的 比较动态适形弧放射治疗(DCAT)与容积旋转调强放射治疗(VMAT)在非小细胞肺癌立体定向放射治疗(SBRT)中的剂量学差异.方法 选取2016年1月至2020年1月于济宁医学院附属医院接受放射治疗的15例非小细胞肺癌患者,用Monaco5.11.03治疗计划系统以相同的目标优化模板和治疗计划参数分别设计DCAT...