直肠癌五野调强放疗与传统适形放疗剂量学研究

Objective  

The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk (OAR) between five-field intensity-modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy (3DCRT) in the radiotherapy of rectal cancer.     

Reliability of the bony anatomy in image-guided stereotactic radiotherapy of brain metastases

PURPOSE: To evaluate whether the position of brain metastases remains stable between planning and treatment in cranial stereotactic radiotherapy (SRT). METHODS AND MATERIALS: Eighteen patients with 20 brain metastases were treated with single-fraction (17 lesions) or hypofractionated (3 lesions) image-guided SRT. Median time interval between planning and treatment was 8 days. Before treatment a cone-beam CT (CBCT) and a conventional CT after application of i.v. contrast were acquired. Setup errors using automatic bone registration (CBCT) and manual soft-tissue registration of the brain metastases (conventional CT) were compared. RESULTS: Tumor size was not significantly different between planning and treatment. The three-dimensional setup error (mean +/- SD) was 4.0 +/- 2.1 mm and 3.5 +/- 2.2 mm according to the bony anatomy and the lesion itself, respectively. A highly significant correlation between automatic bone match and soft-tissue registration was seen in all three directions (r >/= 0.88). The three-dimensional distance between the isocenter according to bone match and soft-tissue registration was 1.7 +/- 0.7 mm, maximum 2.8 mm. Treatment of intracranial pressure with steroids did not influence the position of the lesion relative to the bony anatomy. CONCLUSION: With a time interval of approximately 1 week between planning and treatment, the bony anatomy of the skull proved to be an excellent surrogate for the target position in image-guided SRT.     

Hypofractionation in Hepatocellular Carcinoma – The Effect of Fractionation Size

The use of stereotactic body radiotherapy (SBRT) in hepatocellular carcinoma (HCC) has increased over the years. Several prospective studies have demonstrated its safety and efficacy, and randomised trials are underway. The advancement in technology has enabled the transition from three-dimensional conformal radiotherapy to highly focused SBRT. Liver damage is the primary limiting toxicity with radiation, with the incidence of grade 3 varying from 0 to 30%. The reported radiotherapy fractionation schedule for HCC, and in practice use, ranges from one to 10 fractions, based on clinician preference and technology available, tumour location and tumour size. This review summarises the safety and efficacy of various SBRT fractionation schedules for HCC.     

局部晚期NSCLC适形加陀螺刀放疗与单纯适形放疗的疗效比较

目的:比较适形加陀螺刀放疗与单纯三维适形放疗对局部晚期非小细胞肺癌放射治疗的疗效.方法:将本院40例局部晚期非小细胞肺癌(Ⅲa或Ⅲb期)患者随机分为两组:实验组20例为适形加陀螺刀放疗,对照组20例为单用适形放疗,比较两组间疗效及放射性损伤.结果:实验组有效率(CR+ PR)为95％,对照组有效率为80％,实验组显著高于对照组(P＜0.05);而放射性肺炎两组间无统计学差异.结论:适形加陀螺刀放疗比单用适形放疗可提高近期有效率.     

Intensity-modulated radiotherapy prolongs the survival of patients with nasopharyngeal carcinoma compared with conventional two-dimensional radiotherapy: A 10-year experience with a large cohort and long follow-up

BackgroundTo evaluate the survival benefit of intensity-modulated radiotherapy (IMRT) compared with conventional two-dimensional radiotherapy (2D-CRT) in nasopharyngeal carcinoma (NPC) using a large cohort with long follow-up.MethodsWe retrospectively analysed 7081 non-metastatic NPC patients who received curative IMRT or 2D-CRT from February 2002 to December 2011.ResultsOf the 7081 patients, 2245 (31.7%) were administered IMRT, while 4836 (68.3%) were administered 2D-CRT. At 5 years, the patients administered IMRT had significantly higher local relapse-free survival (LRFS), loco-regional relapse-free survival (LRRFS), progression-free survival (PFS) and overall survival (OS) (95.6%, 92.5%, 82.1% and 87.4%, respectively) than those administered 2D-CRT (90.8%, 88.5%, 76.7% and 84.5%, respectively; p < 0.001). The distant metastasis-free survival (DMFS) was higher for IMRT than 2D-CRT, with borderline significance (87.6% and 85.7%, respectively; p = 0.056). However, no difference was observed between IMRT and 2D-CRT in nodal relapse-free survival (NRFS; 96.3% and 97.4%, respectively; p = 0.217). Multivariate analyses showed that IMRT was an independent protective prognostic factor for LRFS, LRRFS and PFS, but not NRFS, DMFS or OS.ConclusionsIMRT provided an improved LRFS, LRRFS and PFS in both the early and advanced T classifications and overall stage for non-disseminated NPC compared with 2D-CRT. However, no significant advantage was observed in NRFS, DMFS or OS when IMRT was used.     

IMRT联合锥形束CT技术治疗颅内危险区 肿瘤病灶

 目的采用兆伏级锥形束CT(cone-beam computed tomography, CBCT)技术图像引导调强放射治疗（intensity modulated radiotherapy, IMRT）颅内危险区肿瘤病灶,评估其摆位误差及PTV外扩范围。方法对36例颅内肿瘤患者设计IMRT放疗计划,采用西门子ONCOR直线加速器配备的MVision兆伏级CBCT进行三维方向（左右、上下、前后）容积成像并与计划CT图像相匹配获取前5次放射治疗摆位后和摆位误差调整后CBCT数据,分析摆位误差及PTV外扩范围。结果36例患者三维方向摆位误差分别为,左右(2.22±1.37) mm、上下（2.62±1.50） mm和前后（2.77±1.34） mm。摆位误差调整后较调整前摆位误差相比在三维方向均有降低, 并且差异均具有统计学意义（P<0.05）。5次CBCT分次间摆位误差在三维方向上差异均无统计学意义（P>0.05）。若不行CBCT摆位误差校准,PTV在三维方向的外扩范围,左右：2.94 mm, 上下：3.31 mm,前后：3.52 mm。若行CBCT摆位误差校准,PTV在三维方向的外扩范围,左右: 1.00 mm,上下: 1.19 mm,前后: 1.68 mm。结论各个方向的摆位误差边界小于4 mm,采用兆伏级CBCT技术对颅内肿瘤IMRT治疗分次间摆位误差的纠正和PTV边界的评估对提高颅内危险区肿瘤IMRT治疗的精度有重要意义。     

鼻咽癌放疗患者生命质量的影响因素分析

目的:探讨放疗对鼻咽癌患者生命质量的影响,并分析鼻咽癌患者总体生命质量影响因素。方法:以2010年1月至2012年12月我科室行三维适形放疗(3DCRT)或者调强放疗(IMRT)的初治鼻咽癌患者为研究对象,采用QLQ-30中文版调查表分别对两组患者治疗结束时（观察急性放射治疗反应）、治疗结束后三个月（观察亚急性放射治疗反应）及治疗结束后一年（观察慢性反应）鼻咽癌患者的生命质量进行问卷调查。结果:与三维适形放疗比较,调强放疗改善了总体生命质量、社会功能,两者比较差异有统计学意义(P＜0.05),并且家庭经济情况可影响患者的生命质量(P＜0.05)。经过Logistic回归分析提示,对鼻咽癌患者生命质量影响的因素有放疗方式、是否同期化疗、年龄、经济状况及学历。结论:在医疗护理工作中,要综合考虑病情、治疗方式、心理及人口学资料等相关影响因素,为患者选择合理的治疗方案,以期提高患者治疗后的生存质量。     

调强放疗对鼻咽癌患者甲状腺功能的影响

目的 探讨鼻咽癌患者调强放射治疗后早期甲状腺功能的变化情况,为甲状腺功能保护提供依据.方法 收集经病理证实、排除基础甲状腺疾病且接受IMRT治疗的鼻咽癌患者.分析对比放疗前后TT3和TT4水平.结果 全组患者治疗前、后TT3水平分别为1.83 IU/L、1.69 IU/L,治疗前、后TT4水平分别为124.66 IU/L、127.23 IU/L.其中150例(59.8％)治疗后TT3水平下降,变化具有统计学差异(P=0.001).N3患者放疗后血清TT3及TT4水平均明显降低(P值分别为0.043、0.032).结论 IMRT模式下,鼻咽癌患者放疗结束时甲状腺激素降低,N3患者尤为明显.N3患者可运用VMAT/Tomotherapy等技术降低甲状腺照射剂量,且应早期监测甲状腺激素水平,发现问题及早干预.     

Potential of image-guidance, gating and real-time tracking to improve accuracy in pulmonary stereotactic body radiotherapy

Purpose

To evaluate the potential of image-guidance, gating and real-time tumor tracking to improve accuracy in pulmonary stereotactic body radiotherapy (SBRT).

Materials and methods

Safety margins for compensation of inter- and intra-fractional uncertainties of the target position were calculated based on SBRT treatments of 43 patients with pre- and post-treatment cone-beam CT imaging. Safety margins for compensation of breathing motion were evaluated for 17 pulmonary tumors using respiratory correlated CT, model-based segmentation of 4D-CT images and voxel-based dose accumulation; the target in the mid-ventilation position was the reference.

Results

Because of large inter-fractional base-line shifts of the tumor, stereotactic patient positioning and image-guidance based on the bony anatomy required safety margins of 12 mm and 9 mm, respectively. Four-dimensional image-guidance targeting the tumor itself and intra-fractional tumor tracking reduced margins to <5 mm and <3 mm, respectively. Additional safety margins are required to compensate for breathing motion. A quadratic relationship between tumor motion and margins for motion compensation was observed: safety margins of 2.4 mm and 6 mm were calculated for compensation of 10 mm and 20 mm motion amplitudes in cranio-caudal direction, respectively.

Conclusion

Four-dimensional image-guidance with pre-treatment verification of the target position and online correction of errors reduced safety margins most effectively in pulmonary SBRT.     

调强放疗与三维适形放疗治疗局部晚期鼻咽癌的疗效及毒副作用对比

目的 探讨调强放疗(IMRT)与三维适形放疗(3D-CRT)治疗局部晚期鼻咽癌的毒副作用及治疗效果.方法 将120例局部晚期鼻咽癌患者随机分为观察组与对照组,每组60例.观察组采用调强适形放疗,对照组采用三维适形放疗.结果 2组随访时间、生存率及复发率差异无统计学意义(P>0.05).随着时间延长,对照组中耳炎发生率增高速度明显高于观察组(P<0.05);观察组口腔毒副作用占46.67%,消化系统毒副作用占36.67%,血液系统毒副作用占10.00%,皮肤毒副作用占70.00%.对照组口腔毒副作用占56.67%,消化系统毒副作用占46.67%,血液系统毒副作用占16.67%,皮肤毒副作用占90.00%.由于样本量限制,2组未见统计学差异(P>0.05).结论 IMRT与3D-CRT相比,效果相当,但毒副作用相对较小,需要进一步大样本验证.     

三维适形调强放疗治疗食管癌预后的影响因素分析

目的 探讨影响三维适形放疗(3D-CRT)以及调强放疗(IMRT)治疗食管癌患者预后的相关因素.方法 选取85例食管癌患者作为研究对象,其中59例患者接受3D-CRT,26例患者接受IMRT.治疗结束后对患者进行随访.结果 单因素分析显示,性别、年龄、体质指数(BMI)与食管癌患者预后无相关性(P>0.05);病变长度、食管肿瘤最大直径、大体肿瘤体积(GTV)、N分期、T分期、联合化疗与食管癌患者预后相关(P<0.05).多因素分析显示,GTV、N分期、联合化疗是影响3D-CRT以及IMRT治疗食管癌预后的独立相关因素(P<0.05).结论 根据相关因素分析结果,采取相应的措施可改善3D-CRT以及IMRT治疗食管癌的预后.     

常规加IMRT推量放疗联合化疗治疗高分级胶质瘤的疗效和预后因素

Objective:The aim of the study was to retrospectively evaluate the outcomes and important prognostic factors for patients with high-grade gliomas(HGG)treated with conventionalradiotherapy(RT)followed by IMRT as a boost in com bination with chemotherapy.Methods:From November 2004 to November 2006,112 consecutive patients with high-grade gliomas were treated with radiotherapy,which included initial conventional radiotherapy and an IMRT boost to a total dose of 57.5-62.5 Gy,with 27-29 fractions delivered over 37-45 days.All cases received 3-6 cycles of chemotherapy,63 cases received temozolomide,and another 49 cases received methyl-CCNU and teniposide.The acute and late treatment toxicities and the patterns of treatment failure were recorded.The overall survival(OS)rate and progression-free survival(PFS)rate were calculated,and the prognostic factors were analyzed.Results:Most of the acute radiation reactions were grade 1 or 2.No grade 4 acute reactions were noted.Three cases developed radiation necrosis.Grades Ⅰ,Ⅱ,and Ⅲ myelosuppressions were observed in 5,32,and 12 cases of 49 patients treated with teniposide and methyl-CCNU,respectively.Grades Ⅰ and Ⅱmyelosuppressions were observed in 15 and 3 of the 63 patients who were treated with temozolomide,respectively.The 57 cases(50.9%)had recurred locally,and 13 cases(11.6%)had intracranial dissemination.The OS rates at 1,2,and 3 years were 78.9%,54.7%,and 30.8%,respectively.The PFS rates at 1,2,and 3 years were 63.8%,38.9%,and 10.5%,respectively.A multivariate analysis showed that only tumor location and KPS were prognostic factors of OS.These same two variables and histopathology were statistically significant predictive factors in a multivariate analysis for PFS.Conclusion:Radiation toxicities were not found to be increased in this retrospective study with 112 consecutive patients of combined modality therapy including an IMRT boost treatment for HGG.Higher rate of local regional dissemination within the brain was observed than before.Tumor location,histopathology and KPS were important prognostic factors.     

A comparison of optic nerve dosimetry in craniospinal radiotherapy planned and treated with conventional and intensity modulated techniques

Background and purpose

Some CNS tumours present leptomeningeal dissemination. Craniospinal radiotherapy is complex and recurrences may occur at sites of target volume underdosage. IMRT, being highly conformal to the target, could theoretically underdose the optic nerves if they are not specifically targeted leading to optic nerve recurrences. We analyzed optic nerve dosimetry when they are not specifically targeted.

Materials and methods

We designed 3D-conformal and tomotherapy plans for our last five patients treated to the craniospinal axis, not including the optic nerves in the target volume. We analyzed the dose delivered to the optic nerves, to the anterior and posterior half of the optic nerves, and to a theoretical optic nerve-PTV.

Results

The dose delivered to the optic nerves was similar for both plans in all patients (V95% close to 100%) except one in whom tomotherapy considerably underdosed the anterior optic nerves. The dose to the optic nerve-PTV was lower with tomotherapy in all patients.

Conclusion

Despite not intentionally targeting the optic nerves, the dose to the optic nerves with IMRT was similar to 3D-conformal plans in most cases but left no margin for setup error. In individual cases the anterior half of the optic nerves could be significantly underdosed.     

调强放射治疗计划

调强放射治疗（IMRT）作为一种新近发展起来的先进放射治疗技术。在一些发达国家已经应用于临床,其优势在于肿瘤靶区三维剂量分布的适形程度及其均匀性较标准的适形放疗更好,从而在减少或不增加正常组受高剂量照射的前提下增加肿瘤组织的受照剂量,这样就可以提高肿瘤的局部控制率,降低正常组织并发症的发生率,本文对调强放疗的计划过程、剂量计算及优化方式等进行了综述。     

立体定向放射治疗肺癌30例近期疗效分析

目的　评价X -刀立体放疗在晚期肺癌治疗中的价值。方法　 3 0例患者 (原发肿瘤 2 1例 ,转移性肿瘤 9例 ) 47个病灶 ,均采用高剂量分割治疗 ,每周三次 ,分 5～ 8次进行 ,处方剂量 6～ 8Gy ,总量 40～ 48Gy。结果　 17个病灶完全消失 ,2 3个病灶缩小 ,4个病灶无变化 ,3个病灶稍增大 ,肿瘤控制率 93 .6%。结论　立体定向放射治疗晚期肺癌有肯定的近期疗效。     

立体定向放射治疗在复发性卵巢癌中的应用

目的观察X线立体定向放射治疗复发性卵巢癌的临床疗效。方法应用立体定向放射治疗复发性卵巢癌22例。结果22例患者在治疗后1个月症状均有不同程度的缓解,CR 12例(54.5%),PR 5例(22.7%),SD 2例(9.1%),PD 3例(13.6%),总有效率为77.6%。结论X线立体定向放射治疗复发性卵巢癌有较好的近期疗效,且无明显放射性损害反应,可提高患者生活质量,延长患者生存期。     

Defining an optimal role for breast magnetic resonance imaging when evaluating patients otherwise eligible for accelerated partial breast irradiation

Background and purpose

Pre-treatment breast magnetic resonance imaging (MRI) findings in a cohort of women prospectively evaluated for accelerated partial breast irradiation (APBI) are reviewed and characterized to determine the optimal use of MRI in these patients.

Materials and methods

Candidates initially deemed eligible for a prospective APBI trial based on physical examination, mammography, and ultrasound (US) were further evaluated with breast MRI before treatment. All abnormal MRI findings were biopsied.

Results

Between 2002 and 2011, 180 women who met inclusion criteria for APBI underwent breast MRI prior to treatment (median age = 59; range 38–86). 126 tumors (70%) were invasive carcinomas with or without associated DCIS, while 54 (30%) were pure DCIS. Breast MRI confirmed unifocal disease in 109 patients with 111 cancers (60.5% of MRI cohort). Multifocal disease was identified in 19 patients (10.5% of MRI cohort), while multicentric disease was present in 3 patients (1.6% of MRI cohort). Five patients (4%) had an MRI-detected contralateral cancer. False positive MRI findings were seen in 45 patients (25% of MRI cohort). Pre-menopausal patients and patients with tumors >2 cm were more likely to have MRI-detected multifocal/multicentric disease. While there was no statistically significant correlation between multifocal/multicentric disease and breast density, tumor histology, grade, ER status, or Her2/Neu expression, numbers in each category were small, suggesting a lack of statistical power to detect differences that may be clinically meaningful. One hundred and fifty-two of the 180 patients (84.4%) successfully completed lumpectomy and APBI, while 6.7% of the cohort underwent mastectomy.

Conclusions

Breast MRI identified additional disease in 12% of APBI candidates. Premenopausal women and patients with tumors >2 cm were more likely to have MRI-detected multifocal/multicentric disease.     

局部晚期宫颈癌自适应放疗剂量学及生存分析与毒性反应评价

目的： 对比研究自适应调强放疗（adaptive radiation therapy,ART）或单程调强放疗两种不同体外放疗模式治疗局部晚期宫颈癌的剂量学改变及初步临床疗效与毒性反应,探索局部晚期宫颈癌外照射合理模式。方法：收集我院2010年5月至2015年5月间112例行根治性放化疗的局部晚期宫颈癌（FIGO：IIB～IVA期）病例,根据患者外照射模式不同分为两组。A组：单程放疗组,共62例患者,外照射全程未更改放疗计划;B组：自适应放疗组,共50例患者,按首程放疗计划（plan1）照射完成15次（27~30Gy）后重新制定放疗计划（plan2）并且按新计划完成后续治疗。两组患者外照射结束后均接受高剂量率腔内近距离后装治疗。放疗期间两组患者均行顺铂单药同步化疗。比较B组两程计划肿瘤体积和危及器官剂量学改变,并对两组患者进行随访,评价比较患者急慢性毒性反应发生情况及进行生存分析。 结果：B组中plan2与plan1相比,肿瘤平均体积从（107.67±32.02）cm3,退缩到（63.21±25.78）cm3,平均缩小（41.12±13.02）cm3,平均退缩率为（35.48±5.16）%,P＜0.05。直肠平均剂量［Dmean （34.18±0.99）Gy vs.（ 37.09±0.74 ）Gy,P=0.011］、最大剂量［Dmax (50.15±0.69) Gy vs (52.05±0.77) Gy,P=0.003］、1cm3体积受照剂量［(D1cc 48.21±2.02 )Gy vs (49.90±4.19 )Gy,P=0.045］;膀胱平均剂量［Dmean(34.46±0.50）Gy vs (35.36±0.54) Gy,P=0.023］、最大剂量［Dmax（52.53±1.19） Gy vs (54.88±0.89) Gy,P=0.028］、1cm3体积受照剂量［D 1cc（50.60±3.28） Gy vs (52.61±4.64) Gy,P=0.021］,以上剂量指标差异均有统计学意义。A组和B组急性腹泻发生率差异有统计学意义（48.39% vs. 30%,P=0.046）,其它急性及慢性毒性反应发生率差异均无统计学意义。A组和B组患者中位随访时间分别为25个月和27个月,3年总生存率分别为 90.9%和95.2%（P＞0.05）,3年无进展生存率分别为80.4%和93.3%（P＞0.05）。结论：局部晚期宫颈癌外照射过程中肿瘤体积可显著性缩小,采用 ART技术与单程放疗相比3年OS和PFS无明显差异,但ART技术可以降低直肠、膀胱的受照剂量,降低患者治疗期间急性腹泻的发生率。     

小剂量健择联合顺铂方案在鼻咽癌放疗中的增敏价值

[目的]研究每周小剂量健择 顺铂方案(GP)化疗在局部晚期鼻咽癌放射增敏的临床疗效及可行性。[方法]2003年3月至2006年10月,32例初治鼻咽癌患者放疗过程中接受4～7个疗程GP方案增敏化疗。化疗剂量:顺铂12.5mg/(m2·w)、健择125mg/(m2·w)。放疗剂量:鼻咽原发病灶(GTVnx)DT70Gy～76Gy/35～38次,7～8周,颈部淋巴结病灶(GTVnd)DT70Gy/35次,7周,亚临床病灶(CTV)DT50Gy/25次,5周;分别观察GTVnx、GTVnd消失时的放疗剂量,采用RTOG评分标准评价治疗过程的急性放射性反应。[结果]放疗结束时GTVnx、GTVnd完全缓解率分别为93.75%(30/32)和91.67%(22/24),GTVnx、GTVnd消失所需的放射剂量分别为(43.93±12.50)Gy和(48.86±13.69)Gy。无Ⅳ级毒副反应发生。[结论]小剂量GP方案明显增强鼻咽癌的放射敏感性,提高放疗增益,不增加急性放射反应,对晚期鼻咽癌值得进一步研究。