Impact of FDG-PET on radiation therapy volume delineation in non-small-cell lung cancer
Impact of FDG-PET on radiation therapy volume delineation in non-small-cell lung cancer
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DOI：
10.1016/j.ijrobp.2003.10.044
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发表时间：
2004-05-01
影响因子：
7
通讯作者：
Bertrand, RJ
中科院分区：
文献类型：
--
作者：
Bradley, J;Thorstad, WL;Bertrand, RJ
目的：局部失败仍然是接受明确放射治疗或联合化疗的非小细胞肺癌(NSCLC)患者的一个重要问题。[F-18]氟-2-脱氧-D-葡萄糖(FDG)正电子发射断层扫描(PET)已被证明是诊断和分期NSCLC的有价值的工具。通过与单纯CT模拟治疗的比较，确定FDG-PET和CT模拟治疗对放射治疗靶区定义和毒性分布的影响。方法：26例I-III期非小细胞肺癌患者。每个患者在同一天接受序列CT和FDG-PET模拟检查。用于两种模拟的固定装置包括一个阿尔法摇篮、一个平板、6个外部基准标记和一个激光定位系统。一名放射治疗师参与了这两个模拟，以重现治疗方案。CT和融合的PET/CT图像数据集都被传输到放射治疗计划工作站进行轮廓绘制。在绘制肿瘤体积等值线之前，每项FDG-PET研究都要经过解释的核放射科医生的审查。融合后的PET/CT图像用于制定三维适形放射治疗(3DCRT)计划。另一位医生在不知道PET结果的情况下，从CT数据集中勾画出大体肿瘤体积(GTV)和计划目标体积(PTV)的轮廓，并将这些体积用于生成模拟的3DCRT计划。PTV的定义是围绕GTV的10毫米边距。比较两种3DCRT计划的GTV、PTV、平均肺剂量、正常肺体积(V20)和平均食道剂量。结果：26例患者中，8例(31%)FDG-PET发现改变了AJCC的TNM分期，2例根据FDG-PET诊断为转移性疾病并接受姑息性放射治疗。在计划接受3DCRT的24例患者中，14例(58%)的PET明显改变了放射治疗量，如下所示。在3例肺不张患者中，PET有助于区分肺不张与肿块。在10名患者中，PET发现了不可疑的结节病变，1名患者在同一肺叶内发现了单独的肿瘤病灶。靶体积的增加导致平均肺剂量、V20和平均食道剂量的增加。肺不张患者的靶体积减少导致这些正常组织毒性参数的降低。结论：融合FDG-PET和CT图像的放射靶向与CT靶向相比，导致超过50%的患者改变了放射治疗计划。越来越多的一体化PET/CT设备将促进将这项技术用于放射治疗规划。在放射治疗肿瘤学小组内计划进行一项验证性的多中心合作小组试验。(C)2004年爱思唯尔公司。
Purpose: Locoregional failure remains a significant problem for patients receiving definitive radiation therapy alone or combined with chemotherapy for non-small-cell lung cancer (NSCLC). Positron emission tomography (PET) with [F-18]fluoro-2-deoxy-D-glucose (FDG) has proven to be a valuable diagnostic and staging tool for NSCLC. This prospective study was performed to determine the impact of treatment simulation with FDG-PET and CT on radiation therapy target volume definition and toxicity profiles by comparison to simulation with computed tomography (CT) scanning alone.Methods: Twenty-six patients with Stages I-III NSCLC were studied. Each patient underwent sequential CT and FDG-PET simulation on the same day. Immobilization devices used for both simulations included an alpha cradle, a flat tabletop, 6 external fiducial markers, and a laser positioning system. A radiation therapist participated in both simulations to reproduce the treatment setup. Both the CT and fused PET/CT image data sets were transferred to the radiation treatment planning workstation for contouring. Each FDG-PET study was reviewed with the interpreting nuclear radiologist before tumor volumes were contoured. The fused PET/CT images were used to develop the three-dimensional conformal radiation therapy (3DCRT) plan. A second physician, blinded to the results of PET, contoured the gross tumor volumes (GTV) and planning target volumes (PTV) from the CT data sets, and these volumes were used to generate mock 3DCRT plans. The PTV was defined by a 10-mm margin around the GTV. The two 3DCRT plans for each patient were compared with respect to the GTV, PTV, mean lung dose, volume of normal lung receiving greater than or equal to 20 Gy (V20), and mean esophageal dose.Results: The FDG-PET findings altered the AJCC TNM stage in 8 of 26 (31%) patients; 2 patients were diagnosed with metastatic disease based on FDG-PET and received palliative radiation therapy. Of the 24 patients who were planned with 3DCRT, PET clearly altered the radiation therapy volume in 14 (58%), as follows. PET helped to distinguish tumor from atelectasis in all 3 patients with atelectasis. Unsuspected nodal disease was detected by PET in 10 patients, and 1 patient had a separate tumor focus detected within the same lobe of the lung. Increases in the target volumes led to increases in the mean lung dose, V20, and mean esophageal dose. Decreases in the target volumes in the patients with atelectasis led to decreases in these normal-tissue toxicity parameters.Conclusions: Radiation targeting with fused FDG-PET and CT images resulted in alterations in radiation therapy planning in over 50% of patients by comparison with CT targeting. The increasing availability of integrated PET/CT units will facilitate the use of this technology for radiation treatment planning. A confirmatory multicenter, cooperative group trial is planned within the Radiation Therapy Oncology Group. (C) 2004 Elsevier Inc.