Department of Radiation Oncology, RWTH Aachen University Hospital, Germany.
Radiother Oncol. 2011 May;99(2):218-24. doi: 10.1016/j.radonc.2011.03.006. Epub 2011 Apr 16.
Resection is considered as essential for the efficacy of modern adjuvant treatment of glioblastoma multiforme (GBM). Previous studies have indicated that amino acid PET is more specific than contrast enhancement on MRI for detecting residual tumor tissue after surgery. In a prospective study we investigated the prognostic impact of postoperative tumor volume and tumor/brain ratios (TBR) in PET using O-(2-[(18)F]fluoroethyl)-l-tyrosine (FET) in comparison with MRI.
Forty-four patients with GBM were investigated by FET PET and MRI after surgery. Tumor volume in FET PET with a tumor/brain ratio (TBR)>1.6 and a TBR>2, mean and maximum TBR and gadolinium contrast-enhancement on MRI (Gd-volume) were determined. Thereafter patients received a fractionated radiotherapy with concomitant temozolomide (RCX). The median follow-up was 15.4 (3-35) months. The prognostic value of postoperative residual tumor volume in FET PET, TBR(mean,) TBR(max) and Gd-volume was evaluated using Kaplan-Maier estimates for disease-free survival (DFS) and overall survival (OS).
Postoperative tumor volume in FET PET had a significant independent influence on OS and DFS (OS 20.0 vs. 6.9 months; DFS 9.6 vs. 5.1 months, p<0.001; cut-off 25 ml). Similar results were observed when a TBR ≥ 2 (cut-off 10 ml) was used to define the tumor volume in (18)F-FET PET. The TBR(mean) and TBR(max) of FET uptake had a significant influence on DFS (p<0.05). Gd-volume in MRI had significant effect on OS and DFS in the univariate analysis. No independent significant influence in OS or DFS could be observed for Gd-volume in MRI.
Our data indicate that the tumor volume in FET PET after surgery of GBM has a strong prognostic impact for these patients. FET PET appears to be helpful to determine the residual tumor volume after surgery of GBM and may serve as a valuable tool for optimal planning of radiation treatment.
在多形性胶质母细胞瘤（GBM）的现代辅助治疗中，切除被认为是必不可少的。先前的研究表明，与 MRI 上的对比增强相比，氨基酸 PET 更能特异性地检测手术后残留的肿瘤组织。在一项前瞻性研究中，我们使用 O-（2-（18）F）-氟乙基-L-酪氨酸（FET）研究了术后肿瘤体积和肿瘤/脑比值（TBR）对预后的影响，并与 MRI 进行了比较。
44 例 GBM 患者术后行 FET PET 和 MRI 检查。用 FET PET 确定肿瘤体积（TBR）>1.6 和 TBR>2、平均 TBR、最大 TBR 和 MRI 上的钆增强（Gd-体积）。此后，患者接受了卡莫司汀、洛莫司汀和长春新碱的分割放疗（RCX）。中位随访时间为 15.4（3-35）个月。使用无病生存率（DFS）和总生存率（OS）的 Kaplan-Meier 估计值评估 FET PET 术后残留肿瘤体积、TBR（均值）、TBR（最大）和 Gd-体积的预后价值。
FET PET 术后肿瘤体积对 OS 和 DFS 有显著的独立影响（OS 20.0 与 6.9 个月；DFS 9.6 与 5.1 个月，p<0.001；截点 25ml）。当使用 TBR≥2（截点 10ml）定义 FET 摄取的肿瘤体积时，也观察到类似的结果。FET 摄取的 TBR（均值）和 TBR（最大）对 DFS 有显著影响（p<0.05）。MRI 上的 Gd-体积在单因素分析中对 OS 和 DFS 有显著影响。MRI 上的 Gd-体积对 OS 或 DFS 无独立显著影响。
我们的数据表明，GBM 手术后 FET PET 的肿瘤体积对这些患者有很强的预后影响。FET PET 似乎有助于确定 GBM 手术后的残留肿瘤体积，并可能成为放射治疗优化计划的有用工具。
