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.

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。

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.

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。

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;

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。

图像引导放射治疗技术对提高腹部肿瘤放射治疗精准度的效果

目的:分析图像引导放射治疗技术(IGRT)对提高腹部肿瘤放射治疗精准度的效果。方法:选取滨州市中心医院2021年9月—2022年9月收治的腹部肿瘤患者90例为研究对象,采用随机分组方式分为对照组和观察组,各45例。对照组采用逆向调强放疗技术,观察组采用IGRT辅助放射治疗。比较两组患者放射治疗的精准度。结果:观察组适形指数水平高于对照组,均匀性指数水平低于对照组,差异有统计学意义(P=0.001)。观察组肿瘤区域照射量中,相对体积分数(V5)高于对照组,腹部肿瘤平均照射量(D_(mean))低于对照组;周围组织中,观察组V5和D_(mean)低于对照组,差异有统计学意义(P=0.001)。观察组治疗有效率明显高于对照组,差异有统计学意义(P=0.012)。结论:IGRT能提高腹部肿瘤患者放射治疗的精准度,治疗中对患者靶向区域照射量更高,周围组织照射量更低,治疗有效率高。

体重指数对图像引导乳腺癌调强放射治疗摆位误差的影响

目的探讨体重指数(BMI)对保乳术后乳腺癌患者在图像引导治疗下摆位误差及外扩边界的影响。方法回顾性选取2020年1月至2021年7月广州市第一人民医院接受放射治疗的80例保乳乳腺癌患者作为研究对象,根据BMI将患者分成过轻组(BMI<18.4 kg/m^(2))、正常组(18.4 kg/m^(2)≤BMI<24 kg/m^(2))、超重组(24 kg/m^(2)≤BMI<27 kg/m^(2))和肥胖组(BMI≥27 kg/m^(2)),每组20例。放疗时应用锥形束CT(CBCT)进行扫描,采集患者放疗中左右位(LAT)、头脚位(LNG)和腹背位(VRT)三个方向(又分别称X轴、Y轴和Z轴)的摆位误差,计算各组因BMI不同摆位误差的差别,并根据公式MPTV=2.5Σ+0.7σ计算最佳的靶区外扩边界。结果考虑BMI情况下,四组患者X轴和Z轴摆位误差整体比较,差异无统计学意义(P>0.05);四组患者Y轴摆位误差整体比较,差异有统计学意义(P<0.05)。过轻组和正常组X轴上外扩边界相近,超重组和肥胖组X轴上外扩边界相近,但过轻组和正常组小于超重组和肥胖组X轴上的外扩边界;Y轴上的外扩边界随BMI的增大而增大;Z轴上的外扩边界在不同BMI中相近。结论乳腺癌调强放射治疗Y轴摆位误差与BMI存在相关性,随BMI的增大,摆位误差也逐渐增大。不同BMI患者的摆位误差可进一步指导医师确定靶区面积扩边范围,采用不同标准适当扩大或缩小外扩边界,从而提高治疗精度。

头颈部肿瘤螺旋CT引导放射治疗摆位误差分析

目的:利用扇形束螺旋CT系统分析讨论头颈部肿瘤影像引导放射治疗的摆位误差。方法:选取2020年8月至2021年8月,于我院接受影像引导放射治疗的头颈部肿瘤患者128例。分别扫描患者初步摆位后、误差纠正后、治疗结束后的CT图像,将治疗图像与计划图像匹配,获得患者肿瘤靶区中心点在X(左右)、Y(头脚)、Z(腹背)方向上的线性摆位误差,分析误差并讨论。结果:经统计总体线性误差在X、Y、Z方向上平均值分别为(0.91±1.33)、(0.97±1.59)、(0.87±1.28)mm。其中,初步摆位后误差数值分别为(0.98±2.08)、(0.96±2.42)、(0.83±1.79)mm,纠正后的摆位误差分别为(0.11±0.57)、(0.06±0.62)、(0.05±0.75)mm,与初步摆位后误差比较差异有统计学意义(P<0.05)。治疗结束后的摆位误差分别为(0.20±0.86)、(0.25±0.78)、(0.14±0.98)mm,与纠正后的摆位误差比较差异无统计学意义(P>0.05)。结论:在头颈部肿瘤放疗中,应用影像引导放射治疗技术纠正摆位误差可以使治疗个体化,为精确放疗提供了保证,具有推广价值。

直线加速器机载千伏级扇形束CT和兆伏级锥形束CT系统在放疗摆位误差中的应用

目的应用直线加速器机载千伏级扇形束CT(kV-FBCT)及兆伏级锥形束CT(MV-CBCT)定量分析不同治疗部位的肿瘤患者调强放射治疗期间的摆位误差,为制定临床靶区外放边界提供参考。方法回顾性分析我科行放射治疗的患者,分别于每次常规摆位后,调强放射治疗前行kV-FBCT和(或)MV-CBCT扫描,与计划CT配准,纠正摆位,获取每次摆位误差,根据患者的位移计算不同治疗部位患者在左右、前后、头脚方向上的平均位移M、系统误差(Σ)和随机误差(б),通过PTV边界公式(2.5Σ+0.7б)估计在该方向所需要的外放边界。根据同一个患者的单次放疗获得三维位移。结果70例患者共记录到1130人次位移偏差,根据外扩边界公式得出三个方向上所需的PTV边界。头颈1.9~3.1 mm,胸部2.8~5.1 mm,乳腺4.6~5.1 mm,上腹部3.0~5.5 mm及盆腔3.5~6.8 mm。3D平均位移头颈、胸部、乳腺、上腹部和盆腔分别为2.4±1.0 mm、4.0±1.6 mm、4.1±2.0 mm、4.6±2.1 mm及4.6±2.1 mm。利用kV-FBCT和MV-CBCT校位所得3D位移中位值分别为:4.1 mm和3.4 mm,差异无统计学意义(P=0.212)。结论直线加速器机载FBCT均可获得相似的可定量的摆位误差数据,但非等中心的影像引导所致的潜在误差不能忽略。

图像引导放疗CBCT辐照剂量研究现状述评

锥形束CT(cone beam CT,CBCT)普遍用于肿瘤患者放射治疗位置的图像引导,以减少患者治疗摆位误差或自身内部器官运动引入的放疗剂量误差。然而,CBCT扫描产生额外辐照剂量。本文概述了放疗中图像引导的意义、引导设备的优缺点;总结了CBCT辐照剂量研究现状,最后归纳了CBCT辐照剂量研究中的不足。本文将为精确地评价患者在CBCT图像引导过程中受到的辐照剂量提供基础数据,为中国临床医生选择CBCT扫描方案提供理论依据。

图像引导调强放射治疗联合特瑞普利单抗治疗老年局部晚期不能手术非小细胞肺癌的效果

目的探究图像引导调强放射治疗(IGRT)联合特瑞普利单抗治疗局部晚期不能手术治疗的老年非小细胞肺癌(NSCLC)患者的效果。方法选取2019年1—12月泉州市光前医院肿瘤放疗科收治的60例NSCLC患者作为研究对象,随机分为研究组与对照组,每组30例。对照组使用IGRT技术,研究组在对照组基础上联合特瑞普利单抗治疗,比较两组近期疗效、毒副反应发生情况、生存时间。结果研究组临床有效率为86.67%,高于对照组的60.00%,差异有统计学意义(P<0.05);两组疾病控制率比较差异无统计学意义,两组WBC减少、血红蛋白减少、血小板减少、放射性肺炎、放射性食管炎、乏力、发热、心悸、心律失常、甲状腺功能减退发生情况比较差异无统计学意义,两组中位生存时间比较差异无统计学意义。结论IGRT联合特瑞普利单抗治疗局部晚期不能手术治疗的老年NSCLC患者的疗效显著,毒副反应患者可承受,值得临床推广应用。

图像引导调强放射治疗联合重组人血管内皮抑制素泵注治疗局部晚期不能手术的老年非小细胞肺癌患者的疗效

目的探究图像引导调强放射治疗(IGRT)联合重组人血管内皮抑制素(Endostar)泵注治疗局部晚期不能手术的老年非小细胞肺癌(NSCLC)患者的疗效。方法选取2016年10月至2019年9月本院放疗科收治的30例老年NSCLC患者作为研究对象。患者均给予IGRT联合Endostar治疗,观察患者近期疗效、总生存时间。结果患者临床有效率为80.00%,疾病控制率为100.00%,患者毒副作用大多数表现为0~2级,主要为血液学毒性、发热、心律失常、心悸等,中位无进展生存时间为10.4(7.86,14.17)个月,中位生存时间为19.5(14.56,23.45)个月。结论IGRT联合Endostar泵注治疗局部晚期不能手术的老年NSCLC患者疗效确切,毒副作用患者可承受,值得临床推广应用。