国际淋巴瘤放射治疗协作组(ILROG)现代放射治疗靶区勾画及剂量指南——HL

放疗是HL最有效的LC治疗手段和重要的治疗组成部分。这些指南用来指导现代综合治疗条件下放疗在HL中的应用。结合现代影像的三维治疗计划和先进的治疗技术,能减少照射体积和照射剂量。最初使用的EF和IF技术,是基于淋巴结站的大体积治疗方式,目前已被仅以最初可检测到的淋巴结(和结外侵犯)范围为基础的有限的照射野所取代。这种照射技术基于增强CT、PET-CT、MRI或结合运用。ICRU定义了GTV、CTV、ITV和PTV概念。更新的治疗技术包括IMRT、呼吸门控、IGRT和4D图像应用,可以显著降低正常组织损伤风险且同时可达到对原发肿瘤控制的主要目的。能够获得理想治疗前影像患者,可以采用高度适形的受累淋巴结放疗(INRT)。受累部位放疗(ISRT)这个新概念作为标准的适形治疗方式被提出,通常在最佳的影像不可获得的情况下使用。越来越多证据表明过去应用的放疗剂量在综合治疗时代比疾病控制所需剂量高。现有数据支持在早期HL中应用INRT和更低放疗剂量。尽管INRT的应用尚未在正式的研究中得到验证,其应用比ISRT更加保守谨慎,原因为欠理想的影像信息和合适的靶区设计以达到可靠的肿瘤LC。目前使用更小照射野治疗的目标是减少治疗体积和剂量,同时维持治疗有效性并使急性和晚期并发症最小化。这篇综述是ILROG督导委员会关于HL放疗现代治疗手段的共识,概括了对HL在可以达到有效LC的同时减少治疗体积的新概念,即ISRT。     

基于电子直线加速器的肿瘤立体定向放射治疗物理实践指南

立体定向放射治疗具有单次照射剂量大、分割次数少、边缘剂量下降快的特点。治疗过程中应使用最精准的设备,执行最严格、最规范的操作。本指南旨在建立起国内可通用的、立体定向放疗(SRT)临床实践工作所需的医学物理支持的最低要求,帮助国内放疗单位能够正确安全地开展SRT技术。各单位在使用本指南时,需结合本单位SRT设备特点和患者治疗情况,制定明确细致的标准操作程序。     

模拟机对宫颈癌放射治疗摆位不确定度的研究

目的：探讨盆腔源皮距照射的宫颈癌患者在治疗过程中的不确定度。方法：选择首次放疗的宫颈癌患15例,仰卧体位,照射野两侧缘在股骨头内1/3附近,根据肿瘤的范围下缘在耻骨联合下缘,上缘在髂棘（腰椎4,5）水平。根据视野灯在盆腔皮肤上的投影用皮肤墨水勾画出方框,并在模拟机上采集照射野的定位图像,然后实施治疗。在治疗的1至5周,每周在模拟机进行重复摆位,对好病人照射野的方框后在模拟机下重复采集校野图像。将验证体位重复性的校野图像与初次计划时的定位图像进行比较。结果：通过30例患者的100次重复校野图像和初次定位图像相比对,得出同一解剖骨性标志点在x,z轴方向上的移值分别为（10.20±2.50）mm,（5.80±1.00）mm。结论：利用模拟定位多次重复摆位采集校野图像来研究宫颈癌治疗过程中的摆位不确定度是简便,可行的。     

模拟机对宫颈癌放射治疗摆位不确定度的研究

目的:探讨盆腔源皮距照射的宫颈癌患者在治疗过程中的不确定度.方法:选择首次放疗的宫颈癌患15例,仰卧体位,照射野两侧缘在股骨头内1/3附近,根据肿瘤的范围下缘在耻骨联合下缘,上缘在髂棘(腰椎4,5)水平.根据视野灯在盆腔皮肤上的投影用皮肤墨水勾画出方框,并在模拟机上采集照射野的定位图像,然后实施治疗.在治疗的1至5周,每周在模拟机进行重复摆位,对好病人照射野的方框后在模拟机下重复采集校野图像.将验证体位重复性的校野图像与初次计划时的定位图像进行比较.结果:通过30例患者的100次重复校野图像和初次定位图像相比对,得出同一解剖骨性标志点在x,z轴方向上的移值分别为(10.20±2.50)mm,(5.80±1.00)mm.结论:利用模拟定位多次重复摆位采集校野图像来研究宫颈癌治疗过程中的摆位不确定度是简便,可行的.     

鼻腔非何杰金淋巴瘤的放射治疗

 目的:分析鼻腔非何杰金淋巴瘤(NHL)治疗方法和疗效。 方法:1975年6月～1993年3月收治30例鼻腔NHL。 单纯放疗16例, 综合治疗(放疗＋化疗)14例。 照射剂量:<45Gy15例, ≥45Gy15例。 结果:全组5年生存率为70.8％(17/24)。 病变局F民于鼻腔和超出鼻腔组的5年生存率分别为85.7％和50.0％。 单纯放疗组和放疗＋化疗组的5年生存率分别为57.1％和90.0％。 照射剂量<45Gy和≥45Gy的5年生存率分别为64.3％和80.0％。 建议:病变局限于鼻腔者不必做颈部预防性照射。 对病变超出鼻腔或有区域淋巴结受侵者, 应采用放疗与化疗综合治疗。     

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。     

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。     

国际淋巴瘤放射治疗协作组(ILROG)现代放射治疗照射野与剂量指南——结外淋巴瘤(ENL)

ENL约占NHL总数的1/3。放疗常用于初始治疗(尤其是惰性结外淋巴瘤)、系统治疗后的巩固治疗、挽救性治疗以及姑息治疗。由于ENL临床表现多种多样,可以累及全身各器官,病理亚型丰富,给常规临床诊疗以及开展前瞻性和回顾性研究带来诸多困难。不同中心或医生使用的放疗方法亦不尽相同。迄今,ENL的放疗缺乏相关指南。本文中ILROG专家们统一了ENL治疗原则,同时阐述了常见ENL的模拟定位、靶区定义和计划制定,并详尽介绍了放疗靶区勾画方法。本文应用的ISRT新原则,与之前发表的HL和结内NHL指南相同。本文靶区基于ICRU文件,与实体肿瘤相同。此外,本文根据组织分型、解剖结构、治疗目的以及放疗前可能应用的其他治疗模式,为不同器官淋巴瘤放疗给予特殊推荐。     

Ⅰ、Ⅱ期鼻腔非何杰金淋巴瘤的放射治疗——附69例临床分析

本文报道我所1973年1月至1981年3月首次作放疗并完成疗程的Ⅰ、Ⅱ期原发性鼻腔非何杰金淋巴瘤(NHL)69例。着重分析原发病灶照射野的设计及剂量分配,并讨论Ⅰ期患者是否需作颈部予防照射。     

乳腺癌放射治疗切线野的简化摆位技术

乳腺癌的放射治疗多采用切线野照射技术。在乳腺癌的切线野放射治疗时,放疗技术员必须合理的摆放病人的体位,准确地给照射角度、对准照射距离及射野面积,才能使靶区的剂量准确和病人的正常器官和组织得到保护。文献所提出的乳腺癌切线野摆位技术,     

4-Dimensional conformal radiation therapy: image-guided radiation therapy and its application in lung cancer treatment

The goal of all cancer therapies is to increase the therapeutic ratio, that is, to increase the probability of cure while minimizing the toxicity. Theoretically, all cancers can be cured if a sufficient dose of radiation can be delivered to all clonogens without causing undue toxicity to the patient. Obviously, this is not the case in most instances. Precise target localization, in theory, can improve the therapeutic ratio by allowing more conformal radiation delivery, enabling one to escalate the tumor dose while sparing surrounding normal tissue. In the past few decades, conventional 2-dimensional radiation therapy (RT), based on surface anatomy and bony landmarks, has given way to the computed tomography-based 3-dimensional RT, allowing the use of internal soft tissue anatomy. Great interests are now emerging in the field of radiation oncology in assessing the motion of the tumor and surrounding normal tissue, from day to day or during each treatment session, and delivering treatments that adapt to the detected motion. Commercially available 4-dimensional imaging capabilities and various strategies to deliver the radiation dose to the moving target made this new paradigm possible. In this review article, we will discuss the concept of 4-dimensional RT, particularly as it applies to lung cancer, and elaborate on the technical advances that made it possible.     

Radiotherapy for head and neck cancer: an increasing dependence on innovative imaging

Technical improvements in computed tomography and magnetic resonance imaging as well as the wider availability of biological imaging have facilitated the implementation of high-precision 3-dimensional conformal and intensity-modulated radiotherapy (RT) in head and neck cancer. The integration of recent advances in functional and molecular imaging has already improved RT delivery, response prediction, and follow-up. Rational clinical use of all modalities should be encouraged, especially in the setting of imaging-intensive investigational RT protocols such as adaptive therapy. An expanded development of imaging markers that can predict radioresistance or outcome could further customize treatment. The continued successful use of innovative imaging in routine clinical practice will ultimately depend on well-designed clinical studies with adequate follow-up.     

Intensity-modulated radiation therapy for gynecologic cancers: pitfalls, hazards, and cautions to be considered

Intensity Modulated Radiation Therapy (IMRT) is considered a major advance in radiaton therapy (RT) capability. Therefore, it has been rapidly accepted and implemented in the treatment of multiple cancers in which RT plays a major role. Early reports of IMRT in gynecologic cancers have been largely favorable, particularly in terms of decreased acute morbidity. However, IMRT has not been prospectively shown to be superior to conventional 3-dimensional RT techniques when judged against criteria established in advance. Furthermore, there are many reasons to consider the possibility that outcomes might be compromised by IMRT techniques used to treat gynecologic cancers. This article reviews the potential pitfalls and hazards of IMRT techniques on patient safety and treatment efficacy. In addition, the article describes multiple technical issues with IMRT implementation, arguing for caution in IMRT use.     

Recommendations for the Use of Radiotherapy in Nodal Lymphoma

These guidelines have been developed to define the use of radiotherapy for lymphoma in the current era of combined modality treatment taking into account increasing concern over the late side-effects associated with previous radiotherapy. The role of reduced volume and reduced doses is addressed, integrating modern imaging with three-dimensional planning and advanced techniques of treatment delivery. Both wide-field and involved-field techniques have now been supplanted by the use of defined volumes based on node involvement shown on computed tomography (CT) and positron emission tomography (PET) imaging and applying the International Commission on Radiation Units and Measurements concepts of gross tumour volume (GTV), clinical target volume (CTV) and planning target volume (PTV). The planning of lymphoma patients for radical radiotherapy should now be based upon contrast enhanced 3 mm contiguous CT with three-dimensional definition of volumes using the convention of GTV, CTV and PTV. The involved-site radiotherapy concept defines the CTV based on the PET-defined pre-chemotherapy sites of involvement with an expansion in the cranio-caudal direction of lymphatic spread by 1.5 cm, constrained to tissue planes such as bone, muscle and air cavities. The margin allows for uncertainties in PET resolution, image registration and changes in patient positioning and shape. There is increasing evidence in both Hodgkin and non-Hodgkin lymphoma that traditional doses are higher than necessary for disease control and related to the incidence of late effects. No more than 30 Gy for Hodgkin and aggressive non-Hodgkin lymphoma and 24 Gy for indolent lymphomas is recommended; lower doses of 20 Gy in combination therapy for early-stage low-risk Hodgkin lymphoma may be sufficient. As yet there are no large datasets validating the use of involved-site radiotherapy; these will emerge from the current generation of clinical trials. Radiotherapy remains the most effective single modality in the treatment of lymphoma. A reduction in both treatment volume and overall treatment dose should now be considered to minimise the risks of late sequelae. However, it is important that this is not at the expense of the excellent disease control currently achieved.     

Evolution of treatment for nasopharyngeal cancer – Success and setback in the intensity-modulated radiotherapy era

Background and purpose

To assess the therapeutic gains and setbacks as we evolved from the 2-dimensional radiotherapy (2DRT) to conformal 3-dimensional (3DRT) and to intensity-modulated (IMRT) era.

Materials and methods

1593 consecutive patients from 1994 to 2010 were retrospectively analyzed. Evolving changes in the different era included advances in staging investigation, radiotherapy technique, dose escalation, and use of chemotherapy.

Results

The 3DRT era achieved significant improvement in local failure-free rate (L-FFR), disease-specific survival (DSS) and overall survival (OS). Neurological damage and bone/soft tissue necrosis were significantly reduced. However, the improvement in distant failure-free rate (D-FFR) was insignificant, and more hearing impairment occurred due to chemotherapy. Significantly higher D-FFR was achieved in the IMRT era, but L-FFR did not show further improvement. 5-Year DSS increased from 78% in the 2DRT, to 81% in the 3DRT, and 85% in the IMRT era, while the corresponding neurological toxicity rate decreased from 7.4% to 3.5% and 1.8%.

Conclusions

Significant improvement in survival and reduction of serious toxicity was achieved as we evolved from 2DRT to 3DRT and IMRT era; the therapeutic ratio for all T-categories improved with more conformal techniques. Improvements in tumor control were attributed not only to advances in RT technique, but also to better imaging and increasing use of potent chemotherapy. However, it should also be noted that hearing impairment significantly increased due to chemotherapy, L-FFR reached a plateau in the 3DRT era, and it is worrisome that the result for T4 remained unsatisfactory. Besides exploring for more potent chemotherapy and innovative methods, the guideline on dose constraint should be re-visited to optimize the therapeutic ratio.     

Long-term follow-up of patients treated with radiotherapy alone for early-stage histologically aggressive non-Hodgkin's lymphoma

Historically localised aggressive non-Hodgkin's lymphoma (NHL) has been treated with involved field radiotherapy (RT), chemotherapy, or a combination of both modalities. The current weight of evidence supports a preference for combined modality treatment (CMT). Increased patient age at diagnosis is well recognised as a poor prognostic indicator in NHL, but despite this some perceive CMT as too toxic for use in the elderly. As a result, some older patients continue to be offered RT alone. Here, we present long-term follow-up of 377 adults of all ages treated with RT alone for early-stage diffuse large-cell lymphoma on British National Lymphoma Investigation trials between 1974 and 1997. 10-year cause-specific survival in patients older than 60 years was poor and significantly inferior to that in younger patients (47 and 75% respectively; P<0.001). There is growing evidence that short-course chemotherapy, with or without RT, is superior to RT alone in early-stage aggressive NHL, in elderly as well as in younger patients. Increased age alone should not exclude patients from systemic treatment for early-stage aggressive NHL.     

The Gray Lecture 2001: coming technical advances in radiation oncology

PURPOSE: To review the current limits on the efficacy of radiotherapy (RT) due to technical factors and to assess the potential for major improvements in technology. METHODS AND MATERIALS: The method of this review was to assess the efficacy of current RT in general terms; strategies for improving RT; historical record of technological advances; rationale for further reductions of treatment volume; and importance of defining and excluding nontarget tissues from the target volume. The basis for the interest in proton beam RT is developed, and the relative dose distributions of intensity-modulated radiotherapy (IMRT) and intensity-modulated proton RT (IMPT) are discussed. The discovery of the proton and the first proposal that protons be used in RT is described. This is followed by a brief mention of the clinical outcome studies of proton RT. Likely technical advances to be integrated into advanced proton RT are considered, specifically, four-dimensional treatment planning and delivery. Finally, the increment in cost of some of these developments is presented. RESULTS: For definitive RT, dose limits are set by the tolerance of normal tissues/structures adjacent or near to the target. Using imaging fusion of CT, MRI, positron emission tomography, magnetic resonance spectroscopic imaging, and other studies will result in improved definition of the target margins. Proton beams are likely to replace photon beams because of their physical characteristics. Namely, for each beam path, the dose deep to the target is zero, across the target it is uniform, and proximal to the target it is less. Proton therapy can use as many beams, beam angles, noncoplanar, and dynamic, as well as static, intensity modulation, as can photon plans. The ability for much greater accuracy in defining the target position in space and then maintaining the target in a constant position in the radiation beam despite target movement between and during dose fractions will be possible. The cost of proton RT will be modestly higher than comparable high technology photon therapy. CONCLUSION: The technology of RT is clearly experiencing intense and rapid technical developments as pertains to treatment planning and dose delivery. It is predicted that radical dose RT will move to proton beam technology and that the treatment will be four dimensional (the fourth dimension is time). The impact will be higher tumor control probability and reduced frequency and severity of treatment-related morbidity.