Glide-Hurst Carri K, Chetty Indrin J
Henry Ford Health Systems, Detroit, MI, USA.
J Thorac Dis. 2014 Apr;6(4):303-18. doi: 10.3978/j.issn.2072-1439.2013.11.10.
In the United States, more than half of all new invasive cancers diagnosed are non-small cell lung cancer, with a significant number of these cases presenting at locally advanced stages, resulting in about one-third of all cancer deaths. While the advent of stereotactic ablative radiation therapy (SABR, also known as stereotactic body radiotherapy, or SBRT) for early-staged patients has improved local tumor control to >90%, survival results for locally advanced stage lung cancer remain grim. Significant challenges exist in lung cancer radiation therapy including tumor motion, accurate dose calculation in low density media, limiting dose to nearby organs at risk, and changing anatomy over the treatment course. However, many recent technological advancements have been introduced that can meet these challenges, including four-dimensional computed tomography (4DCT) and volumetric cone-beam computed tomography (CBCT) to enable more accurate target definition and precise tumor localization during radiation, respectively. In addition, advances in dose calculation algorithms have allowed for more accurate dosimetry in heterogeneous media, and intensity modulated and arc delivery techniques can help spare organs at risk. New delivery approaches, such as tumor tracking and gating, offer additional potential for further reducing target margins. Image-guided adaptive radiation therapy (IGART) introduces the potential for individualized plan adaptation based on imaging feedback, including bulky residual disease, tumor progression, and physiological changes that occur during the treatment course. This review provides an overview of the current state of the art technology for lung cancer volume definition, treatment planning, localization, and treatment plan adaptation.
在美国，所有新诊断出的侵袭性癌症中，超过一半是非小细胞肺癌，其中相当一部分病例在局部晚期阶段出现，导致约三分之一的癌症死亡。虽然立体定向消融放疗（SABR，也称为立体定向体部放疗或SBRT）应用于早期患者已将局部肿瘤控制率提高到>90%，但局部晚期肺癌的生存结果仍然严峻。肺癌放射治疗存在重大挑战，包括肿瘤运动、低密度介质中的精确剂量计算、限制对附近危及器官的剂量以及治疗过程中解剖结构的变化。然而，最近引入了许多可以应对这些挑战的技术进步，包括四维计算机断层扫描（4DCT）和容积锥形束计算机断层扫描（CBCT），分别用于在放疗期间实现更精确的靶区定义和肿瘤定位。此外，剂量计算算法的进步使得在异质介质中进行更精确的剂量测定成为可能，强度调制和弧形放疗技术有助于保护危及器官。新的放疗方法，如肿瘤跟踪和门控，为进一步缩小靶区边界提供了额外潜力。图像引导自适应放射治疗（IGART）基于成像反馈，包括大块残留病灶、肿瘤进展和治疗过程中发生的生理变化，为个性化计划调整带来了可能。本综述概述了肺癌靶区定义、治疗计划、定位和治疗计划调整的当前技术水平。
