Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
J Nucl Med. 2010 Oct;51(10):1532-8. doi: 10.2967/jnumed.110.078592. Epub 2010 Sep 16.
6-(18)F-fluoro-l-dopa ((18)F-FDOPA) measured with PET as a biomarker of amino acid uptake has been investigated in brain tumor imaging. The aims of the current study were to determine whether the degree of (18)F-FDOPA uptake in brain tumors predicted tumor grade and was associated with tumor proliferative activity in newly diagnosed and recurrent gliomas.
Fifty-nine patients (40 men, 19 women; mean age ± SD, 44.4 ± 12.3 y) with newly diagnosed (n = 22) or recurrent (n = 37) gliomas underwent (18)F-FDOPA PET perioperatively. Tumor tissue was obtained by resection or biopsy in all patients. The tumor grade and Ki-67 proliferation index were obtained by standard pathology assays. Tumor (18)F-FDOPA uptake was quantified by determining various standardized uptake value (SUV) parameters (mean SUV, maximum SUV [SUVmax], mean values of voxels with top 20% SUVs, and tumor-to-normal-brain tissue ratios) that were then correlated with histopathologic grade and Ki-67 proliferation index.
Fifty-nine lesions in 59 patients were analyzed. (18)F-FDOPA uptake was significantly higher in high-grade than in low-grade tumors for newly diagnosed tumors (SUVmax, 4.22 ± 1.30 vs. 2.34 ± 1.35, P = 0.005) but not for recurrent tumors that had gone through treatment previously (SUVmax, 3.36 ± 1.26 vs. 2.67 ± 1.18, P = 0.22). An SUVmax threshold of 2.72 differentiated low-grade from high-grade tumors, with a sensitivity and specificity of 85% and 89%, respectively, using receiver-operating-characteristic curve analysis (area under the curve, 0.86). (18)F-FDOPA PET uptake correlated significantly with Ki-67 tumor proliferation index in newly diagnosed tumors (r = 0.66, P = 0.001) but not in recurrent tumors (r = 0.14, P = 0.41).
(18)F-FDOPA uptake is significantly higher in high-grade than in low-grade tumors in newly diagnosed but not recurrent tumors that had been treated previously. A significant correlation between (18)F-FDOPA uptake and tumor proliferation in newly diagnosed tumors was observed, whereas this correlation was not identified for recurrent tumors. Thus, (18)F-FDOPA PET might serve as a noninvasive marker of tumor grading and might provide a useful surrogate of tumor proliferative activity in newly diagnosed gliomas.
确定脑肿瘤中（18）F-FDOPA 的摄取程度是否可预测肿瘤分级，并与新诊断和复发性神经胶质瘤的肿瘤增殖活性相关。
59 例新诊断（n=22）或复发性（n=37）神经胶质瘤患者[40 例男性，19 例女性；平均年龄（±SD）44.4±12.3 岁]接受了（18）F-FDOPA PET 围手术期检查。所有患者均通过切除或活检获得肿瘤组织。通过标准病理学检测获得肿瘤分级和 Ki-67 增殖指数。通过确定各种标准化摄取值（SUV）参数（平均 SUV、最大 SUV [SUVmax]、最高 20%SUV 像素的平均值和肿瘤与正常脑组织的比值）来量化肿瘤（18）F-FDOPA 摄取情况，然后将其与组织病理学分级和 Ki-67 增殖指数相关联。
59 例患者的 59 个病变被分析。新诊断肿瘤中，高级别肿瘤的（18）F-FDOPA 摄取明显高于低级别肿瘤（SUVmax：4.22±1.30 比 2.34±1.35，P=0.005），但此前经治疗的复发性肿瘤中未见此差异（SUVmax：3.36±1.26 比 2.67±1.18，P=0.22）。使用受试者工作特征曲线分析（曲线下面积，0.86），SUVmax 阈值为 2.72 可将低级别肿瘤与高级别肿瘤区分开来，具有 85%的敏感性和 89%的特异性。（18）F-FDOPA PET 摄取与新诊断肿瘤中的 Ki-67 肿瘤增殖指数显著相关（r=0.66，P=0.001），但与复发性肿瘤中未见此相关性（r=0.14，P=0.41）。
在新诊断但未经治疗的肿瘤中，高级别肿瘤的（18）F-FDOPA 摄取明显高于低级别肿瘤，但在先前经治疗的复发性肿瘤中未见此差异。在新诊断肿瘤中观察到（18）F-FDOPA 摄取与肿瘤增殖之间存在显著相关性，而在复发性肿瘤中未发现这种相关性。因此，（18）F-FDOPA PET 可能是肿瘤分级的一种非侵入性标志物，并可能为新诊断的神经胶质瘤的肿瘤增殖活性提供有用的替代指标。
