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

Modern radiation therapy for hodgkin lymphom-target definition and dose guidelines from the international lymphoma radiation oncology group

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。

Radiation therapy （RT） is the most effective single modality for local control of Hodgkin lymphoma （HL） and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional （3D） planning and advanced techniques of treatment delivery. The previously applied extended field （EF） and original involved field （IF） techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal （and extranodal extension） involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy （INRT）, recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy （ISRT）, is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the use of ISRT has not yet been validated in a formal study, it is more conservative than INRT, accounting for suboptimal information and appropriately designed for safe local disease control. The goal of modern smaller field radiation therapy is to reduce both treatment volume and treatment dose while maintaining efficacy and minimizing acute and late sequelae. This review is a consensus of the International Lymphoma Radiation Oncology Group （ILROG） Steering Committee regarding the modern approach to RT in the treatment of HL, outlining a new concept of ISRT in which reduced treatment volumes are planned for the effective control of involved sites of HL.