全中枢放疗精确定位的CT模拟技术

介绍CT模拟技术在全中枢神经系统放疗中的应用,CT模拟定位系统中融合全束照射技术、半束照射技术、低熔点铅挡技术、等中心照射技术、两野衔接技术,利用三维治疗计划系统优化治疗计划,实现传统全中枢神经系统放疗向高精度放射治疗的转变。     

全中枢神经系统放射治疗新技术探讨

目的:探讨全中枢神经系统放射治疗更加合理、实用的新技术。方法:应用放疗计划系统针对成人和儿童患者分别制定四种不同照射方法的放疗计划,并比较各放疗计划的剂量分布指标。结果:经对比观察分析,几种计划方法在成人和儿童患者各有优缺点。结论:根据患者个体情况采用CT模拟定位、放疗计划系统、三维适形调强放疗技术为基础的多种全中枢系统照射技术方法,结合计划验证和图像引导技术指导治疗计划实施,都具有一定的实用性和较强的准确性、安全性。     

癌性脑膜炎的放射治疗(附17例分析)

目的　通过对 17例癌性脑膜炎治疗效果的分析 ,探讨放射治疗对该病的治疗及预后的影响。方法　 17例经临床 ,影像学或CSF细胞学检查证实的癌性脑膜炎患者。 15例行放疗 ,1例未完成治疗 ,1例因恶液质不宜放疗。结果　 10例接受全脑放疗者 ,9例中枢神经系统症状及体征改善 ;4例行全脑 +脊髓节段照射 ,3例中枢神经系统及神经根表现明显改善 ,1例症状无改变。 2例经全脑脊髓照射后脑部及神经根症状均改善。脑膜CT及MRI示局部病变消失2例 ,缩小 8例 ,稳定 3例 ;脊髓CT、MRI检查示局部病变缩小 1例 ,未控 1例。照射者中位生存期 6.7个月。中断治疗患者及恶液质各 1例均在 2月内死亡。结论　对癌性脑膜炎行短程放射治疗 ,可降低治疗费用 ,缩短治疗时间 ,提高生存质量。     

三维CT模拟定位计划系统的临床应用研究

[目的]通过三维CT模拟定位计划系统的临床应用研究。评价其在放疗听作用。[方法]将螺旋CT,三维激光定位系统和Focus9200三维计划系统通过网络连接,形成放疗科专用的,集影像诊断,图像传送,肿瘤定位和三维计划为一体的三维CT模拟定位计划系统。分别对143例肿瘤病人进行CT模拟定位和治疗计划。[结果]CT模拟定位和X线模拟定位一样可完成从定位到体表标记的全过程,利用CT进行定位,可为靶区的确定,复杂多野照射,适形调强放疗以及立体定向放疗提供更多的图像信息和更高的定位精度,使治疗中心和实际靶中心的重复误差小于1mm。[结论]CT模拟定位可用于大多数肿瘤病人的定位,是实现高精度放疗的必备设备之一。     

重复CT在局部晚期鼻咽癌调强放疗过程中应用的初步研究

调强放疗计划是在疗前模拟定位CT基础上制定,且未考虑治疗过程中患者解剖结构发生改变的因素.如果用一计划全程照射,靶区和危及器官剂量可在放疗期间发牛变化,因此利用重复CT来研究局部晚期鼻咽痛患者调强放疗过程中解剖结构改变及其对剂量影响.     

三维适形放射治疗计划照射野位置的模拟验证

目的:验证三维适形放疗(3dimentional conformal radiotherapy,3DCRT)计划的照射野精度。方法:应用放射治疗模拟定位机对372例三维适形放疗计划的照射野进行治疗过程模拟,观察其与实际预照射目标的吻合性及铅模质量。结果:在治疗模拟中发现三维适形放疗计划照射野和铅模存在一定误差,最大误差2.1cm,最小误差0.3cm,误差率为5.1%(19/372)。结论:应用放射治疗模拟定位机对三维适形放疗计划照射野精度验证,方法简便,及时纠正了各种误差,可推广使用。     

容积旋转调强技术行全脑放疗联合转移灶同期加量治疗脑转移瘤的剂量学研究

目的 探讨容积旋转调强(volume modulated arc therapy,VMAT)技术行全脑放疗联合转移灶同期加量治疗脑转移瘤的可行性.方法 选取10例行放疗的脑转移瘤患者,每例患者同时设计两种放疗计划:RA计划和Sum计划.RA计划全程采用VMAT技术,全脑照射30 Gy/10 F,同时转移灶同期加量照射45 Gy/10 F;Sum计划全脑适形对穿照射30 Gy/10F后,采用VMAT技术对转移灶局部加量照射15 Gy/5 F.比较两种计划的靶区剂量分布、危及器官及转移灶外脑组织的受照射剂量、机器跳数等.结果 两种计划靶区剂量分布均满足临床要求.RA计划靶区适形度指数优于Sum计划(0.99±0.00vs 0.77±0.05,P＜0.001),全脑V35、V.亦显著小于Sum计划(P＜0.05),机器跳数较Sum计划减少约12％.结论 RA计划的靶区剂量分布可达到或优于Sum计划,能更好地降低转移灶外正常脑组织的受照射剂量,减少机器跳数.应用VMAT技术行全脑放疗联合转移灶同期加量是制定脑转移瘤放疗计划的一种优选方式.     

三维适形放射治疗计划照射野位置的模拟验证

目的：验证三维适形放疗（3dimentional conformal radiotherapy,3DCRT）计划的照射野精度。方法：应用放射治疗模拟定位机对372例三维适形放疗计划的照射野进行治疗过程模拟,观察其与实际预照射目标的吻合性及铅模质量。结果：在治疗模拟中发现三维适形放疗计划照射野和铅模存在一定误差,最大误差2.1cm,最小误差0.3cm,误差率为5.1%（19/372）。结论：应用放射治疗模拟定位机对三维适形放疗计划照射野精度验证,方法简便,及时纠正了各种误差,可推广使用。     

乳腺癌保乳术后全乳野中野适形调强放射治疗技术

目的:探讨乳腺癌保乳术后全乳野中野适形调强照射技术方法,并与常规全乳切线野照射技术进行剂量学对比.方法:选取22例早期乳腺癌保乳术后患者在CT模拟机下对乳腺部位行薄层定位扫描,将定位图像传输至治疗计划系统进行全乳野中野计划设计:在全乳两切线适形野的基础上挡去高剂量区部分,另设计2-4个小跳数射野以降低靶区最高剂量和调整高剂量区的范围及所在位置.处方剂量50Gy/25次,要求95%的靶区接受处方剂量;然后利用其CT模拟定位资料按照常规切线野射野方法在治疗计划上模拟常规切线野治疗计划,对野中野计划和常规射野计划进行靶区适形性、靶区均匀性和危及器官受量的比较.结果:野中野适形调强放射治疗技术的适形度、均匀性优于常规切线野照射,靶区内超过110%处方剂量的体积明显小于常规切线野技术.减少了肺组织V20的体积,降低了心脏的平均剂量和受照体积.结论:乳腺癌保乳术后全乳野中野适形调强放射治疗技术是一种有益的全乳照射技术.     

乳腺癌保乳术后全乳野中野适形调强放射治疗技术

目的：探讨乳腺癌保乳术后全乳野中野适形调强照射技术方法,并与常规全乳切线野照射技术进行剂量学对比。方法：选取22例早期乳腺癌保乳术后患者在CT模拟机下对乳腺部位行薄层定位扫描,将定位图像传输至治疗计划系统进行全乳野中野计划设计：在全乳两切线适形野的基础上挡去高剂量区部分,另设计2—4个小跳数射野以降低靶区最高剂量和调整高剂量区的范围及所在位置。处方剂量50Gy／25次,要求95％的靶区接受处方剂量;然后利用其CT模拟定位资料按照常规切线野射野方法在治疗计划上模拟常规切线野治疗计划,对野中野计划和常规射野计划进行靶区适形性、靶区均匀性和危及器官受量的比较。结果：野中野适形调强放射治疗技术的适形度、均匀性优于常规切线野照射,靶区内超过110％处方剂量的体积明显小于常规切线野技术。减少了肺组织V20的体积,降低了心脏的平均剂量和受照体积。结论：乳腺癌保乳术后全乳野中野适形调强放射治疗技术是一种有益的全乳照射技术。     

Management of CNS disease in ALK-positive non-small cell lung cancer: Is whole brain radiotherapy still needed?

Anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (3 to 5% of all non-small cell lung cancers) carries a particularly high risk of central nervous system dissemination (60% to 90%). As the use of ALK inhibitors improves treatment outcomes over chemotherapy, the determent of central nervous system metastases has become an increasingly relevant therapeutic dilemma considering young age and possible extended overall survival. The goal of brain metastases management is to optimize both overall survival and quality of life, with the high priority of neurocognitive function preservation. Unfortunately in the first year on crizotinib, the pioneering ALK inhibitors, approximately one third of these patients fail in the central nervous system, which is explained by an inadequate central nervous system drug penetration through the blood-brain barrier. Central nervous system-directed radiotherapy represents the most important strategy to control intracranial disease burden and extend the survival benefit with crizotinib. The role of whole brain irradiation in the treatment of brain metastases diminishes, as this technique is associated with the risk of neurocognitive decline. Stereotactic radiotherapy represents an alternative technique that delivers ablative doses of ionizing radiation to the limited volume of oligometastatic brain disease, offering sparing of the adjacent brain parenchyma and reduced neurotoxicity. The next generation ALK inhibitors were designed to cross the blood-brain barrier more efficiently than crizotinib and achieve higher concentration in the cerebrospinal fluid, offering prominent ability to control central nervous system spread. In the phase III ALEX trial the intracranial control was significantly better with alectinib as compared to crizotinib and it translated into survival benefit. Other next generation ALK inhibitors (i.e. ceritinib, brigatinib, lorlatinib) also demonstrated promising activity in the central nervous system.     

全中枢神经系统放射治疗最佳布野探讨

目的：探讨全中枢神经系统放射治疗中,脊髓布野及全脊髓野与全脑野间衔接的方法。方法：采用我院与浙江大学联合研制的平移扫描治疗装置,在^60Co治疗机上对全脊髓进行平移扫描照射以及用一个等中心、半束整体铅摸照射全脑。结果：根据测量全脊髓内及脊髓与全脑衔接处以及全脑内剂量分布满意,无冷点或热点,符合QA。讨论：全中枢神经系统放射治疗时,采用平移扫描治疗全脊髓及等中心半束整体铅模照射全脑．全脑、髓内以及衔接处剂量满意。     

Brain dose-sparing radiotherapy techniques for localized intracranial germinoma: Case report and literature review of modern irradiation

We examined the effects of intensity-modulated radiation therapy with dose-sparing and avoidance technique on a pediatric patient with localized intracranial germinoma. We also reviewed the literature regarding modern irradiation techniques in relation to late neurocognitive sequelae. A patient with a localized intracranial germinoma in the third ventricle anterior to the pineal gland received a dose-sparing intensity-modulated radiation therapy. The planning was compared to the radiation oncologist's guide of organs at risk and dose constraints for dosimetric analyses. The patient received radiation therapy alone. The total dose was 54 Gy delivered in 2.0 Gy fractions to the primary tumour and 37 Gy in 1.4 Gy fractions to whole ventricles using a dose-sculpting plan. Dosimetry analyses showed that dose-sparing intensity-modulated radiation therapy delivered reduced doses to the whole brain, temporal lobes, hippocampi, cochleae, and optic nerves. With a follow-up of 22 months, failure-free survival was 100% for the patient and no adverse events during radiation treatment process. Intensity-modulated radiation therapy with dose sparing and avoidance technique can spare the limbic circuit, central nervous system, and hippocampus for pineal germ cell tumours. This technique reduces the integral dose delivered to the uninvolved normal brain tissues and may reduce late neurocognitive sequelae caused by cranial radiotherapy.     

非小细胞肺癌脑转移放疗研究进展

自20世纪50年代全脑放疗首次应用于脑转移以来,一直被视为非小细胞肺癌脑转移的标准治疗方案。近年来,随着放疗技术越来越精准、全身治疗方案越来越有效,特别是分子靶向药物以目不暇接的速度更新换代,其靶向性更强、中枢神经系统渗透性更好,患者生存期延长,WBRT的神经系统远期损伤引起广泛关注。本文将对现代综合治疗模式下的非小细胞肺癌脑转移,全脑放疗的相关争议及进展进行综述。     

原发中枢神经系统淋巴瘤放疗作用观察

目的 探索放疗在原发中枢神经系统淋巴瘤治疗中的作用。方法 回顾分析2010年9月至2017年12月确诊的免疫功能正常的原发中枢神经系统淋巴瘤60例资料,其中50例经由手术或立体定向活检后病理诊断,10例影像学临床诊断。52例患者接受了化疗,其中45例为大剂量甲氨喋呤为主方案,25例为含利妥昔单抗方案。27例患者行计划性放疗,33例未行计划性放疗,其中治疗失败后9例接受了挽救性放疗。结果 中位随访时间28个月(5~70个月)。全组中位生存、中位无进展生存期分别为22个月(5~65个月)、13个月(5~55个月),4年总生存率、无进展生存率分别为61%、33%。计划性放疗组、非计划性放疗组4年总生存率分别为68%、54%(P=0.083),无进展生存率分别为47%、20%(P=0.014)。挽救性放疗组与计划性放疗组4年总生存率差异无统计学意义(P=0.398),全脑放疗≤36Gy、>36Gy组4年总生存率差异也无统计学意义(P=0.136)。结论 放疗是原发中枢神经系统淋巴瘤的综合治疗的一部分,计划性放疗可能使患者在综合治疗中获益,较高的照射剂量不能使患者获益。     

以替尼泊苷为主的化疗方案治疗中枢神经系统淋巴瘤

目的：观察以替尼泊苷为主的化疗方案治疗中枢神经系统淋巴瘤的疗效。方法：8例原发性／继发性中枢神经系统(CNS)非霍奇金淋巴瘤(NHL)患者，给予COP+VM-26方案化疗，7例给予全颅放疗，4例在放、化疗前手术切除颅内病灶。结果：4例原发性CNS-NHL患者中3例手术切除后化疗，1例患者未手术，仅采用放疗和化疗，4例均获得了完全缓解，中位无病生存时间23.5月，中位总体生存时间29月；对系统性NHLⅣ期伴有颅内浸润的患者，该方案可以迅速缓解CNS症状，3／4例CR。结论：以替尼泊苷为主的化疗方案对CNS-NHL疗效较好。CNS-NHL的治疗应采用综合疗法，即手术+化疗+放疗。     

Brain tumors after cranial irradiation for childhood acute lymphoblastic leukemia. A 13-year experience from the Dana-Farber Cancer Institute and the Children's Hospital

Brain tumors developed in two children after they had received cranial irradiation as central nervous system therapy for acute lymphoblastic leukemia. A review of the literature demonstrated an increased incidence of brain tumors in survivors of acute lymphoblastic leukemia who received central nervous system irradiation. Most of the brain tumors occurred within a decade after radiotherapy. Further data will be required to determine whether early post-radiation brain tumors in patients with acute lymphoblastic leukemia are due to the central nervous system irradiation or to a genetic predisposition.     

Partial irradiation of the brain

Late radiation injury is the main dose-limiting factor for radiotherapy of tumors of the central nervous system (CNS). Clinical experience as well as analyses of complication data, both for brain necrosis and for changes in neuroimaging after radiosurgery, suggest a pronounced volume effect in the brain. However, the relationships of dose and volume to complications after irradiation of lesions in the brain have yet to be quantitatively assessed. The quantification of volume effects and the modeling of normal tissue response to partial organ irradiation of the brain are particularly demanding because of the highly differentiated and complex structure of the brain and the variety of endpoints after radiotherapy for CNS diseases. This article summarizes the existing clinical data that demonstrate a volume effect in the brain and the current state of knowledge regarding the modeling of complications following partial irradiation of the brain.     

螺旋断层放射治疗系统在中枢神经系统肿瘤中的应用

螺旋断层放射治疗系统（helical tomotherapy,HT）是利用一台6MV的医用直线加速器以螺旋CT旋转扫描方式,实现40 cm×160 cm范围的照射,是当今最先进的肿瘤放射治疗系统之一,集调强放射治疗（IMRT）、图像引导放射治疗（IGRT）、自适应放疗 (ART）和剂量引导放疗（DGRT）于一体。目前HT已初步应用于中枢神经系统良恶性肿瘤的治疗,照射精确、剂量分布均匀、能够有效保护危及器官,降低正常组织放疗毒性,应用前景广阔。现就HT在中枢神经系统肿瘤中的应用展开总结论述。