Delineation of Brain Tumor Extent with [11C]l-Methionine Positron Emission Tomography

Abstract

ABSTRACT

62Cu-Diacetyl-Bis (N4-Methylthiosemicarbazone) PET in Human Gliomas: Comparative Study with [18F]Fluorodeoxyglucose and L-Methyl-[11C]Methionine PET

“…MET readily crosses the intact BBB through a neutral amino acid transporter and is incorporated into active tumor areas, which allows tumor visualization even in lowgrade gliomas. 9 In our current study, MET-PET revealed a significant difference between GBM and non-GBM despite the high frequency of oligodendroglial tumors. However, these oligodendroglial tumors are reported to show relatively high uptake of MET irrespective of their grade on MET-PET, 3,4 19 Our preliminary clinical study also showed that 62 Cu-ATSM uptake values correlated highly with hypoxia-inducible factor-1␣ expression, which is a biomarker of tissue hypoxia, 14 and the optimal cutoff threshold to predict hypoxia-inducible factor-1␣ expression (T/B ratio, 1.8) was similar to that of our present study in the prediction of GBM (T/B ratio, 1.9).…”

“…14 The uptake regions of the FDG and MET images were extracted on the basis of the T/B ratio thresholds of Ն1.5 and Ն1.3, respectively, in accordance with previous reports. 5,9 These uptake regions were rated as metabolically active volumes. For GBM, we extracted the tumor volume by measuring a completely covered contrast-enhanced region with necrotic and cystic components on MR imaging.…”

“…2 This increased transport and high metabolism oc-cur commonly in GBM and can be detected by widely used techniques, such as FDG-PET and L-methyl-[ 11 C]methionine (MET)-PET. [3][4][5][6][7][8][9] However, the predictive value of these PET imaging techniques has not been adequate for a diagnosis of GBM because uptake of these tracers is not specific in GBM. 3,4 On the other hand, tissue hypoxia and necrosis are cardinal features of GBM that are often associated with resistance to radiation therapy and chemotherapy.…”

Imaging in neurooncology

“…21,86 Uptake is increased not only in solid parts of the tumor but also in the infiltration area. 91,92 In 80% of gliomas WHO II°[ 11 C]MET-uptake is greater than 1.5-fold of the normal brain tissue, 21 whereas glucose metabolism is reduced compared with gray matter. Most studies indicated that [ 11 C]MET-uptake is inversely correlated to prognosis, [93][94][95] 78,96 and exceeds the area of involvement depicted by Gd-enhanced MRI.…”

11C‐methionine uptake and intraoperative 5‐aminolevulinic acid‐induced fluorescence as separate index markers of cell density in glioma

“…In particular, increasing evidence suggests the utility of 11 C-methionine PET for the purpose of delineating the tumor invasion area. 5 On the other hand, fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) has been developed to achieve the same goal. This technique enables intraoperative detection of tumor tissue that is hard to distinguish from surrounding normal tissue under conventional white-light microscope illumination.…”