Spinal cord biological safety of image-guided radiation therapy versus conventional radiation therapy

Tumor models were simulated in purebred Beagles at the T9-10 levels of the spinal cord and treated with spinal image-guided radiation therapy or conventional radiation therapy with 50 or 70 Gy total radiation. Three months after radiation, neuronal injury at the T9-10 levels was observed, including reversible injury induced by spinal image-guided radiation therapy and apoptosis induced by conventional radiation therapy. The number of apoptotic cells and expression of the proapoptotic protein Fas were significantly reduced, but expression of the anti-apoptotic protein heat shock protein 70 was significantly increased after image-guided radiation therapy compared with the conventional method of the same radiation dose. Moreover, the spinal cord cell apoptotic index positively correlated with the ratio of Fas/heat shock protein 70. These findings indicate that 3 months of radiation therapy can induce a late response in the spinal cord to radiation therapy; image-guided radiation therapy is safer and results in less neuronal injury compared with conventional radiation therapy.

IGRT联合周剂量紫杉醇同期放化疗不能手术食管癌疗效评价

目的评价图像引导调强放疗(IGRT)联合周剂量紫杉醇持续静脉滴注同期放化疗不能手术食管癌的疗效及毒副反应。方法 2014-2015年50例不能手术的食管鳞癌入组,非手术临床分期为Ⅱ-Ⅲ期。行CT模拟定位,图像引导调强放疗(IGRT),总剂量为63Gy,放疗第一天即配合化疗(具体方案:紫杉醇45mg/m^2 CIV 16h d1 qW×6)。结果近期总有效率为98%,1、2年随访的病人数分别为46、34例,1、2年的局部控制率分别为92%、78%,1、2年的总生存率分别为92%、68%,急性毒副反应的主要表现是骨髓抑制,以白细胞减少、中性粒细胞减少为主,非血液学毒性反应轻微。结论 IGRT联合周剂量紫杉醇持续静脉滴注同期放化疗不能手术食管癌的局部控制率高,在应用集落刺激因子后骨髓抑制可以耐受。

CTVision和MV-CBCT两种IGRT技术在放疗摆位中的应用

目的:对大孔径CT和MV-CBCT图像引导的放射治疗流程的介绍以及利用两种方法获得的摆位误差进行分析,比较两种图像引导方式在放疗摆位应用中的不同之处。方法:15例患者(鼻咽癌5例,前列腺癌4例,宫颈癌6例)治疗前分别进行CT和MV-CBCT图像采集,并与计划CT进行图像融合,MV-CBCT采用自动配准方式,CT采用自动+手动配准方式,分析两组数据,探讨CTVision和MV-CBCT两种IGRT的应用。结果:CTVision和MV-CBCT对15例病人图像引导的方式在X、Y、Z方向的摆位误差均没有统计学意义,但Y方向的误差有一定差异。结论:CTVision图像更为清晰,采集时需要剂量更少,但所需时间较长,技术员需进出机房两次。【关键词】CTVision;MV-CBCT;

Adaptive Dose-Compensation Technique for Image-Guided Radiotherapy of Prostate Cancer

Background: For image-guided radiotherapy(IGRT) of prostate cancer, the current standard is online image guidance which can effectively correct setup errors and inter-fraction rigid organ motion. However, planning margins are still necessary for deformation and intra-fraction motion. Objective: This paper aims to investigate an adaptive planning technique incorporating offline dose feedback to manage interfraction motion and residuals from online corrections. Methods:Repeated CT scans from 28 patients were studied. Online IG was simulated by matching center-of-mass of prostate. A seven-beam IMRT plan with zero margins was designed for each patient. Dose distribution at each fraction was evaluated based on actual target and OARs from that fraction. Cumulative dose was calculated using deformable registration and compared to initial plan. If deviation exceeded pre-defined 2% threshold in prostate D99 an adaptive planning technique called dose compensation was invoked, in which cumulative dose was fed back to the planning system and dose deficit was made up through boost radiation in future fractions through IMRT. Results: If 2% under-dose was allowed at the end of course, then 11 patients failed. If the same criteria was assessed at the end of each week(every 5 fractions), then 14 patients failed. The average dose deficit for these 14 patients was4.4%. They improved to 2% after weekly compensation. 10(out of 14) patients passed criterion after weekly dose compensation; 3 failed marginally; 1 failed significantly(10% deficit). A more aggressive compensation frequency(every 3 fractions) could reduce the dose deficit to the acceptable level for this patient. The doses to OARs were not significantly different from online IG only without dose compensation.Conclusion: We demonstrated an offline dose compensation technique in prostate IGRT which can effectively account for residual uncertainties uncorrectable in online IG. Dose compensation allows further margin reduction and critical organs sparing.

局部光动力并IGRT同步中药治疗肿瘤的临床疗效分析

目的探讨局部光动力治疗(photodynamic therapy,PDT)并影像引导下适形调强治疗(Image guide radiation therapy,IGRT)同步中药辅助整合对肿瘤治疗的剂量效应及临床疗效,为中晚期空腔脏器及表浅肿瘤患者提供不同策略有效综合治疗的依据。方法对160例手术失败或无手术适应症的空腔或浅表肿瘤患者,采用局部与区域联合全身的综合治疗方案,观察分析20min vs.30min、200J/cm2vs.300J/cm2、1次vs.3次光化物理疗法(PCT/PDT)不同时间、剂量、分次(TDF)与IGRT并同步中医药治疗的量效关系。结果 PDT物理疗法与IGRT同步中医药治疗,随着TDF的变化有显著统计意义,PDT对中晚期肿瘤特别是空腔脏器患者,可显著减轻症状,提高患者生活质量;对梗阻型、放化疗失败的中晚期肿瘤患者有较高姑息治疗价值。结论采用PDT联合IGRT与中药不同策略的整合治疗,通过TDF的优化同步中医药的辅助方案,创伤性小、副作用少,可达到减毒增效、带瘤生存的目的,使中晚期空腔脏器及表浅肿瘤患者"变不治为可治"。

IGRT技术在校正胸腹部恶性肿瘤大分割放疗误差中的应用价值

目的探讨图像引导放射治疗（IGRT）技术在校正胸腹部恶性肿瘤大分割放疗时的误差及价值。方法对31例经病理诊断明确为胸腹部恶性肿瘤患者行大分割放疗。分次照射剂量为3～12 Gy,总剂量为30～54 Gy,其中分次剂量3 Gy为3例,5 Gy为8例,6 Gy为9例,8 Gy为7例,12 Gy为4例。每次治疗前行锥型束CT,在线校正摆位误差并记录误差值。结果校正后均数标准差在左右（X）、头脚（Y）和腹背（Z）方向上分别为（2.02±2.18）mm、（2.26±2.28）mm和（2.02±2.13）mm。结论应用IGRT技术在线校位能有效减小摆位误差,对及时发现肿瘤靶区变化情况和适时调整临床放射治疗方案有重要意义。

Treatment of Massive Low-Grade Chondrosarcoma of Nasal Septum with Helical Tomotherapy: A Case Report

Chondrosarcomas are malignant bone tumors which develop as a cartilaginous differentiation of primary mesenchymal cells and the second most frequently seen malignant tumor of the bone after osteosarcoma. These malignancies are slowly growing non-epithelial tumors with unknown etiology and most frequently seen during the 4 decades of life. They are frequently localized on pelvis, ribs and long bones. Nasal septum CSs are very rarely seen malignancies. They originate from septal mucosa or cartilage and it is difficult to make a diagnosis unless they reach a certain size. A few cases of CSs with nasal septum have been reported in the literature. In cases of CSs, surgery is the gold standard treatment modality;however in surgically unresectable cases or close to margins, radiotherapy plays a significant role in primary and adjuvant treatment. Based on the position of the tumor in head and neck and extremely closeness of the tumor to vital organs as optic nerve, chiasm and brain, image guided-intensity modulated radiation therapy (IG-IMRT) becomes very effective and reliable modalities and may be a favorable treatment alternative.

Precision radiotherapy for brain tumors A 10-year bibliometric analysis

OBJECTIVE： Precision radiotherapy plays an important role in the management of brain tumors. This study aimed to identify global research trends in precision radiotherapy for brain tumors using a bibliometric analysis of the Web of Science. DATA RETRIEVAL： We performed a bibliometric analysis of data retrievals for precision radiotherapy for brain tumors containing the key words cerebral tumor, brain tumor, intensity-modulated radiotherapy, stereotactic body radiation therapy, stereotactic ablative radiotherapy, imaging-guided radiotherapy, dose-guided radiotherapy, stereotactic brachytherapy, and stereotactic radiotherapy using the Web of Science. SELECTION CRITERIA： Inclusion criteria： （a） peer-reviewed articles on precision radiotherapy for brain tumors which were published and indexed in the Web of Science; （b） type of articles： original research articles and reviews; （c） year of publication： 2002-2011. Exclusion criteria： （a） articles that required manual searching or telephone access; （b） Corrected papers or book chapters. MAIN OUTCOME MEASURES： （1） Annual publication output; （2） distribution according to country; （3） distribution according to institution; （4） top cited publications; （5） distribution according to journals; and （6） comparison of study results on precision radiotherapy for brain tumors. RESULTS： The stereotactic radiotherapy, intensity-modulated radiotherapy, and imaging-guided radiotherapy are three major methods of precision radiotherapy for brain tumors. There were 260 research articles addressing precision radiotherapy for brain tumors found within the Web of Science. The USA published the most papers on precision radiotherapy for brain tumors, followed by Germany and France. European Synchrotron Radiation Facility, German Cancer Research Center and Heidelberg University were the most prolific research institutes for publications on precision radiotherapy for brain tumors. Among the top 13 research institutes publishing in this field, seven are in the USA, three are in Germany, two are in France, and there is one institute in India. Research interests including urology and nephrology, clinical neurology, as well as rehabilitation are involved in precision radiotherapy for brain tumors studies. CONCLUSION： Precision radiotherapy for brain tumors remains a highly active area of research and development.

中晚期食道癌IGRT放疗同步化疗的疗效

目的：观察中晚期食道癌影响引导适形调强放疗（IGRT）精确放疗同步化疗的疗效及不良反应.方法：2010年10月至2012年12月本院本科收治的中晚期食道癌患者56例,随机分为两组,治疗组28例,同步予以紫素（TXT）＋顺铂（PPD）化疗,21 d为1周期,共2周期,1～3个月后,巩固化疗3～4周期;对照组28例,单纯IGRT精确放疗.结果：治疗组有效率85.7%,对照组有效率67.9%,主要不良反应为放射性食道炎、恶心、呕吐等消化道反应,骨髓抑制有统计学意义,治疗组完全脱发率100%.结论：中晚期食道癌IGRT精确放疗同步化疗安全有效,其不良反应患者可耐受.

SIB-IGRT联合埃克替尼治疗EGFR突变型肺腺癌脑转移的前瞻性随机对照研究

目的探讨同期加量的图像引导调强放疗(SIB-IGRT)联合埃克替尼治疗表皮生长因子受体(EGFR)突变型肺腺癌脑转移的效果。方法纳入70例EGFR突变型肺腺癌脑转移患者,按照随机数字表法将其分为同步治疗组和先放疗组,各35例。同步治疗组于埃克替尼靶向治疗第1天开始进行SIB-IGRT,先放疗组于埃克替尼靶向治疗前15 d开始进行SIB-IGRT。比较两组患者的近期疗效[疾病控制率(DCR)、客观缓解率(ORR)]、远期疗效[无进展生存时间(PFS)],以及不良反应发生情况。结果(1)同步治疗组患者的ORR、DCR均高于先放疗组,PFS长于先放疗组(均P<0.05);同步治疗组患者的恶心、呕吐、疲乏发生率均低于先放疗组(均P<0.05)。结论SIB-IGRT联合埃克替尼同步治疗可提高EGFR突变型肺腺癌脑转移患者的DCR及ORR,并可延长患者的PFS,不良反应较少,值得临床推广应用。

Target migration from re-inflation of adjacent atelectasis during lung stereotactic body radiotherapy

Stereotactic body radiotherapy(SBRT) is a widely accepted option for the treatment of medically inoperable early-stage non-small cell lung cancer(NSCLC).Herein,we highlight the importance of interfraction image guidance during SBRT.We describe a case of earlystage NSCLC associated with segmental atelectasis that translocated 15 mm anteroinferiorly due to re-expansion of the adjacent segmental atelectasis following the first fraction.The case exemplifies the importance of crosssectional image-guided radiotherapy that shows the intended target,as opposed to aligning based on rigid anatomy alone,especially in cases associated with potentially "volatile" anatomic areas.

46例早期乳腺癌保乳术后IGRT疗效分析

目的：观察早期乳腺癌保乳术后影像引导适形调强放疗（ IGRT ）临床疗效及不良反应。方法：收集2010年10月～2013年3月，我科治疗的46例早期乳腺癌患者保乳术后行IGRT的临床资料，评价疗效和不良反应。结果：经过保乳术后进行IGRT的患者，在中位19个月的随访后，无远处转移，除1例外无出现局部复发。患者的放疗反应轻微。结论：早期乳腺癌保乳术后IGRT安全有效，患者副作用可耐受。

对用于肺部自适应放疗的合成CT影像质量的对比研究

目的评估基于Velocity软件,不同锥形束CT(Cone Beam CT,CBCT)扫描模式下对应的合成CT(synthetic CT,sCT)的图像质量。方法通过设置CIRS肺运动模体常规的呼吸运动状态,对其进行4D-CT模拟定位。在平均密度投影CT即计划CT(planning CT,pCT)上完成计划设计后,将其传至TrueBeam直线加速器,分别实现3D-CBCT和4D-CBCT的扫描和图像重建,再基于Velocity软件得到相应的sCT。结果sCT图像保留了基准pCT图像的精细结构,且二者图像轮廓之间有较强的相关性,所有Dice相似系数都超过0.85。通过直观对比可看出,相比对应的CBCT图像,sCT图像伪影明显减少。sCT3D/sCT4D图像中不同感兴趣区的CT值均明显更低,sCT的噪声更小。对sCT而言,sCT3D图像的CT值的平均百分差异为7.68%,sCT4D图像的CT值的平均百分差异为4.65%。相比3D-CBCT,基于4D-CBCT得到的sCT图像的CT值精度得到了改善。结论在固定呼吸状态下,基于Velocity得到的对应不同模式CBCT的sCT图像质量与基准pCT可以相比拟,与呼吸相关的图像引导在肺癌患者放疗时更有临床价值。

锥形束CT图像引导在胸部肿瘤患者放疗摆位中的实施效果

目的分析在胸部肿瘤患者放疗摆位中应用锥形束CT图像引导的效果。方法选择2020年1月—2023年7月曹县人民医院收治的40例胸部肿瘤患者为研究对象,所有患者均接受常规电子射野影像仪图像检查与锥形束CT图像检查,分别作为对照组与研究组,比较两组不同方向摆位偏差、时间相关指标。结果研究组患者的不同方向摆位偏差均低于对照组低,差异有统计学意义(P均<0.05)。研究组的摆位时间为(150.52±14.29)s,长于对照组的(49.53±15.29)s,差异有统计学意义(t=30.519,P<0.05)。两组图像获取时间比较,差异无统计学意义(P>0.05)。结论在胸部肿瘤患者放疗摆位中实施锥形束CT图像检查可减少方向摆位偏差。

MRI引导放射治疗的应用现状及发展趋势

放射治疗的精准性受靶区勾画、摆位误差、分次间和分次内器官运动等因素的影响。近年来,随着医学技术的不断发展,放射治疗的精准性取得了重大进步,尤其是图像引导放射治疗(IGRT)的应用,有效减少了各种影响因素的不确定性。MRI引导放射治疗(MRIgRT)使用MRI代替锥形束CT(CBCT),利用MRI特有的影像学优势,可在线、实时跟踪肿瘤运动和生物学变化,实现自适应放射治疗(ART),是放射治疗史上的一项重要技术进步。该研究就MRIgRT的应用现状及发展趋势进行综述。

图像引导下的大分割调强放射治疗骨转移癌临床研究

目的：本研究采用图像引导下的大分割调强放疗技术,治疗癌症骨转移.评价该方案的可行性、安全性及有效率.方法：选取我科2011～2012年收治椎体骨转移患者21名,骨转移灶28处,予肿瘤所在椎体24 Gy/6次,同步予肿瘤加量至36 Gy/6次,限制脊髓D0.1ml小于25 Gy.结果：病灶疗前疼痛评分7.54±0.84分;疗后即刻评分4.00±1.59分,缓解程度47.38％±17.75％;疗后1月评分2.46±2.01分,缓解程度67.54％±24.84％;疗后3月评分2.07±1.92分,缓解程度72.92％±24.09％.治疗后即刻、1月、3月疼痛评分较疗前均有显著差异（P＜0.01）.疗后即刻有效率为57.14％（16/28）,1月有效率为82.14％（23/28）,3月有效率为82.14％（23/28）.l例患者出现Ⅱ度食管副反应,无患者出现神经系统副反应.结论：本研究表明图像引导下的大分割调强放射治疗骨转移癌是安全有效的治疗选择,其长期疗效尚需进一步研究.

不同解剖区域配准方法对鼻咽癌体位误差的影响

目的：在鼻咽癌图像引导调强放疗中,采用4种不同解剖区域进行图像配准,研究分析4种配准方法对鼻咽癌体位误差的影响。方法：应用Varian23IX IGRT系统对17例鼻咽癌患者治疗时进行图像采集,选择颅底（A方法）、颈椎1~3（B方法）、下颌骨（C方法）和整体配准（D方法）等4种方法对CT-CBCT图像进行在线或离线配准,分别分析4种配准方法造成的线性误差（Vrt,Lng,Lat）及旋转误差（Pitch,Roll,Rtn）。结果：由于应用A、B、C等3种配准方法时,所选兴趣区域较小,只分析了各自区域的误差,故误差略大于D方法;且部分区域（如下颌骨）在摆位时会随后仰状态而变化,Lng误差略高于A和C方法;颈椎C1~C3也会随颈部的扭动而变化,旋转误差略高于A和C方法。而D方法所选兴趣区域较大,在线配准时可以对各兴趣区域信息进行整合,寻找较均衡的分析结果,配准结果较好。结论：图像引导放射治疗在鼻咽癌放疗中可以在线纠正摆位误差以提高放疗的精度,整体配准方法配准结果较好。

CyberKnife系统技术评估和临床应用评价

介绍了Cyber Knife系统作为最新型的立体定向放射治疗设备之一的独有优势,同时提出了临床上其仍然存有一定局限性且有待被重新认识。最后对Cyber Knife系统的技术特点及临床应用情况进行了评估和总结,指出不断拓展治疗空间、提升引导图像中组织解剖信息是Cyber Knife系统未来发展的方向。

研究体板结合真空垫及热塑膜技术与传统臂部支撑固定技术在胸部肿瘤放疗摆位中的误差

背景与目的:放射治疗已进入了精确放疗的时代,摆位误差成为影响放疗效果的重要因素。通过采用两种不同体位固定方式,即自行改装后的体板结合真空垫及热塑膜的固定装置和臂部支撑装置,讨论分析胸部肿瘤放疗中的摆位误差。方法:选择肺及食管胸部肿瘤患者19例,随机分成两组,分别采用体板+真空垫+体部热塑膜固定(A组)、臂部支撑装置固定(B组)进行摆位和治疗。A组利用二次摆位技术,即先使患者头脚方向的激光线与真空垫上的定位标记一致,再根据患者体表定位标记进行摆位(第一次摆位),最后覆上热塑膜固定,再根据热塑膜上的定位标记移床至治疗位置(第二次摆位);B组利用一次摆位技术,即直接根据体表标记进行摆位。A、B组均利用千伏级锥形束CT(kilo-voltage cone beam computed tomography,KVCBCT)采集治疗前﹑后的图像,并与计划CT图像配准,得到治疗前及治疗后的体位误差并进行统计分析。结果:对于两种不同固定方式,A组和B组治疗前误差分别为:X轴(左右方向)(1.06±0.58)和(1.82±0.82)mm,Y轴(头脚方向)(1.31±0.40)和(2.18±1.20)mm,Z轴(腹背方向)(1.28±0.66)和(2.94±1.81)mm。治疗后误差分别为:X轴(0.86±0.54)和(1.29±0.58)mm,Y轴(1.07±0.58)和(1.08±0.45)mm,Z轴(0.98±0.53)和(1.56±0.63)mm。结论:A组误差均小于B组,采用体板结合真空垫及热塑膜固定装置并应用二次摆位技术的患者,在放疗过程中不仅摆位的精确度得以提高,同时也保证了体位的重复性及稳定性。

图像引导放疗技术在直肠癌患者术前调强放疗中的应用

目的:探讨图像引导放疗技术(IGRT)在直肠癌患者术前新辅助调强放疗(IMRT)中的应用,分析其对靶区勾画的指导意义。方法:67例临床分期为Ⅱ~Ⅲ期(T3-4N0M0或T1-4N1-2M0)的直肠癌患者行术前IMRT,放疗期间每周行1次IGRT,获得术前和术后的2组影像在三维空间的对比位置误差,计算系统误差(Σ)和随机误差(σ),按照Van Herk公式计算计划靶区扩边值(MPTV)。结果:389个CBCT扫描图像在x、y、z 3个轴位方向上的误差范围分别为(0.86^-1.13)、(1.94^-2.11)及(1.87^-1.81)cm。校正后y轴和z轴上的平移误差小于校正前(t=3.541,P=0.001;t=3.275,P=0.000);校正后x轴和y轴上的旋转误差小于校正前(t=1.260,P=0.000;t=2.797,P=0.000。校正前,x、y、z 3个轴位方向上的MPTV分别为2.00、3.25和2.88cm,校正后为0.73、1.74和1.50cm,分别减少了1.27、1.51及1.38cm。结论:IGRT可减少直肠癌患者术前IMRT的系统误差和摆位误差,是精确放疗的有效质量保证。