Munck Af Rosenschold Per, Costa Junia, Engelholm Svend Aage, Lundemann Michael J, Law Ian, Ohlhues Lars, Engelholm Silke
Department of Oncology, Section of Radiotherapy, Rigshospitalet, Copenhagen, Denmark (P.M.a.R., J.C., S.A.E., M.J.L., L.O.); Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark (P.M.a.R., M.J.L.); Department of Clinical Physiology, Nuclear Medicine, and PET, Rigshospitalet, Copenhagen, Denmark (I.L., J.C.); Section of Radiation Oncology, Skåne University Hospital, Lund, Sweden (S.E.).
Neuro Oncol. 2015 May;17(5):757-63. doi: 10.1093/neuonc/nou316. Epub 2014 Dec 23.
We sought to assess the impact of amino-acid (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade glioma versus the current standard using MRI alone. Specifically, we investigated the influence of tumor grade, MR-defined tumor volume, and the extent of surgical resection on PET positivity.
Fifty-four consecutive high-grade glioma patients (World Health Organization grades III-IV) with confirmed histology were scanned using FET-PET/CT and T1 and T2/fluid attenuated inversion recovery MRI. Gross tumor volume and clinical target volumes (CTVs) were defined in a blinded fashion based on MRI and subsequently PET, and volumetric analysis was performed. The extent of the surgical resection was reviewed using postoperative MRI.
Overall, for ∼ 90% of the patients, the PET-positive volumes were encompassed by T1 MRI with contrast-defined tumor plus a 20-mm margin. The tumor volume defined by PET was larger for glioma grade IV (P < .001) and smaller for patients with more extensive surgical resection (P = .004). The margin required to be added to the MRI-defined tumor in order to fully encompass the FET-PET positive volume tended to be larger for grade IV tumors (P = .018).
With an unchanged CTV margin and by including FET-PET for gross tumor volume definition, the CTV will increase moderately for most patients, and quite substantially for a minority of patients. Patients with grade IV glioma were found to be the primary candidates for PET-guided radiation therapy planning.
我们试图评估氨基酸（18）F-氟乙基酪氨酸（FET）正电子发射断层扫描（PET）对高级别胶质瘤放射治疗的体积靶区定义的影响，与仅使用磁共振成像（MRI）的当前标准进行对比。具体而言，我们研究了肿瘤分级、MRI定义的肿瘤体积以及手术切除范围对PET阳性的影响。
对54例经组织学确诊的连续高级别胶质瘤患者（世界卫生组织III-IV级）进行FET-PET/CT以及T1和T2/液体衰减反转恢复序列MRI扫描。基于MRI随后是PET，以盲法定义大体肿瘤体积和临床靶区（CTV），并进行体积分析。使用术后MRI评估手术切除范围。
总体而言，约90%的患者中，PET阳性体积被T增强MRI定义的肿瘤加20毫米边缘所包含。PET定义的肿瘤体积在IV级胶质瘤中更大（P < 0.001），在手术切除范围更广的患者中更小（P = 0.004）。为了完全包含FET-PET阳性体积而需要添加到MRI定义的肿瘤上的边缘，IV级肿瘤往往更大（P = 0.018）。
在CTV边缘不变的情况下，通过纳入FET-PET进行大体肿瘤体积定义，大多数患者的CTV将适度增加，少数患者会大幅增加。发现IV级胶质瘤患者是PET引导放射治疗计划的主要候选者。
