Oriuchi N, Tomiyoshi K, Inoue T, Ahmad K, Sarwar M, Tokunaga M, Suzuki H, Watanabe N, Hirano T, Horikoshi S, Shibasaki T, Tamura M, Endo K
Department of Nuclear Medicine, Gunma University School of Medicine, Japan.
J Nucl Med. 1996 Mar;37(3):457-62.
SPECT with 201TI is an effective procedure for evaluating the malignancy of glioma. Our goal was to investigate the diagnostic relevance of both 201TI SPECT and [18F]fluorodeoxyglucose (FDG) PET and the relation between 201TI uptake and glucose metabolism in glioma using comparative SPECT and PET studies.
Thallium-201 SPECT and FDG dynamic PET studies were performed in 20 patients with untreated glioma (5 with glioblastoma, 5 with anaplastic glioma, 10 with low-grade glioma). Thallium-201 uptake in the tumor was estimated using the 201TI index, defined as the ratio of 201TI uptake in the tumor to that in the contralateral normal brain on SPECT images obtained 15 min after intravenous injection. We measured regional glucose metabolic parameters, including rate constants and regional cerebral metabolic rate of glucose utilization (rCMRgl), in the tumor. We then compared the regional 201TI index and glucose metabolic parameters with the histologic characteristics, malignancy and computed tomographic/ magnetic resonance imaging findings. In addition, we investigated the correlation between the 201TI index and glucose metabolic parameters.
Thallium-201 SPECT showed abnormal 201TI uptake in all patients with glioblastoma and anaplastic glioma. Thallium-201 indices of glioblastoma (202.6 +/- 22.1%) and anaplastic glioma (176.6% +/- 26.6%) were significantly higher than that for low-grade glioma (106.7% +/- 13.8%). The rCMRgl value of glioblastoma (17.6 +/- 3.5 mumole/100 g/min) was also significantly higher than that for low-grade glioma (10.8 +/- 4.5 mumole/100 g/min), although rCMRgl showed a large variability in both high- and low-grade glioma. Rate constants of FDG kinetics had no correlation with histological grade of glioma. Some patients with high-grade glioma, however, showed false-negative results with FDG-PET because of high normal brain uptake of FDG. Conversely, most low-grade glioma could not be localized by 201TI SPECT. There was no correlation between the 201TI index and glucose metabolic parameters.
Thallium-201 indices and rCMRgl values for glioblastoma were higher than those for low-grade glioma. Thallium-201 uptake in the tumor may be independent of increased glucose transport or metabolism. Thallium-201 SPECT and FDG-PET are complementary in the diagnosis of glioma, although 201TI SPECT is more significantly correlated with the malignancy of glioma.
201铊单光子发射计算机断层扫描（SPECT）是评估神经胶质瘤恶性程度的有效方法。我们的目标是通过对比SPECT和正电子发射断层扫描（PET）研究，探讨201铊SPECT和[18F]氟脱氧葡萄糖（FDG）PET的诊断相关性以及神经胶质瘤中201铊摄取与葡萄糖代谢之间的关系。
对20例未经治疗的神经胶质瘤患者（5例胶质母细胞瘤、5例间变性神经胶质瘤、10例低级别神经胶质瘤）进行了201铊SPECT和FDG动态PET研究。使用201铊指数估计肿瘤中的201铊摄取，201铊指数定义为静脉注射15分钟后在SPECT图像上肿瘤中201铊摄取与对侧正常脑组织中201铊摄取的比值。我们测量了肿瘤中的区域葡萄糖代谢参数，包括速率常数和区域脑葡萄糖代谢率（rCMRgl）。然后，我们将区域201铊指数和葡萄糖代谢参数与组织学特征、恶性程度以及计算机断层扫描/磁共振成像结果进行了比较。此外，我们还研究了201铊指数与葡萄糖代谢参数之间的相关性。
201铊SPECT显示所有胶质母细胞瘤和间变性神经胶质瘤患者均有异常的201铊摄取。胶质母细胞瘤（202.6±22.1%）和间变性神经胶质瘤（176.6%±26.6%）的201铊指数显著高于低级别神经胶质瘤（106.7%±13.8%）。胶质母细胞瘤的rCMRgl值（17.6±3.5微摩尔/100克/分钟）也显著高于低级别神经胶质瘤（10.8±4.5微摩尔/100克/分钟），尽管rCMRgl在高级别和低级别神经胶质瘤中均有较大变异性。FDG动力学的速率常数与神经胶质瘤的组织学分级无关。然而，一些高级别神经胶质瘤患者由于正常脑组织对FDG摄取较高，FDG-PET显示假阴性结果。相反，大多数低级别神经胶质瘤不能通过201铊SPECT定位。201铊指数与葡萄糖代谢参数之间无相关性。
胶质母细胞瘤的201铊指数和rCMRgl值高于低级别神经胶质瘤。肿瘤中201铊摄取可能与葡萄糖转运或代谢增加无关。201铊SPECT和FDG-PET在神经胶质瘤诊断中具有互补性，尽管201铊SPECT与神经胶质瘤恶性程度的相关性更强。
