Contributions of biological tumor parameters to the incorporation rate of l-[methyl-11C] methionine into astrocytomas and oligodendrogliomas

Abstract

We compared the tumor uptake of 11 C-methionine (MET) with positron emission tomography (PET) with the results of a pathological analysis to examine the proliferative potential and microvessel density measured with immunostaining for MIB-1 and factor VIII, respectively, from 33 patients with glioma. The MET uptake in oligodendrogliomas was significantly greater than that in grade 2 astrocytomas and comparable to those in grade 3 and 4 astrocytomas. The MIB-1 index of oligodendroglioma meanwhile was comparable to that of grade 2 astrocytoma. The microvessel area in oligodendroglioma was significantly greater than that in grade 2 astrocytomas and comparable to those in grade 3 and 4 astrocytomas. According to a multivariate statistical analysis, MET uptake ratio was closely correlated with the MIB-1 index among astrocytomas. An increase in the microvessel area in the oligodendrogliomas contributed to the higher MET uptake among the tumors with a low-proliferative index. This information is important for interpreting the results of MET-PET studies for clinical use.

Correlation between positron emission tomography findings and glucose transporter 1, 3 and L-type amino acid transporter 1 mRNA expression in primary central nervous system lymphomas

“…The uptake of FDG and MET was found to be dependent on proliferative activity, as well as on other factors, such as MVD (23,24) and CD (25). In oligodendrocytic tumors, abundant microvessels and̸or high CD may occasionally cause increased uptake of FDG and MET (23).…”

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

“…[33][34][35][36] Some of those reports have shown positive correlations between the T/N ratio of 11 C-methionine PET and the Mib-1 labeling index, which reflects tumor proliferation capability. [34][35][36] On the other hand, others have shown a positive correlation between the T/N ratio and microvessel density, which is considered to reflect angiogenesis. 33 It should be noted that these nonstereotactic studies seem less accurate compared with stereotactic image-histology comparisons, as gliomas consist of heterogeneous tissues.…”

“…32,33 Previous reports have analyzed correlations among 11 C-methionine uptake, tumor proliferative ability, and angiogenesis. 22,[33][34][35][36] Several reports have been based on a comparison of the highest indices of each of these parameters. [33][34][35][36] Some of those reports have shown positive correlations between the T/N ratio of 11 C-methionine PET and the Mib-1 labeling index, which reflects tumor proliferation capability.…”

“…22,[33][34][35][36] Several reports have been based on a comparison of the highest indices of each of these parameters. [33][34][35][36] Some of those reports have shown positive correlations between the T/N ratio of 11 C-methionine PET and the Mib-1 labeling index, which reflects tumor proliferation capability. [34][35][36] On the other hand, others have shown a positive correlation between the T/N ratio and microvessel density, which is considered to reflect angiogenesis.…”

The future of neuro-oncology

“…These data suggest that imaging parameters that rely on revealing an abnormal blood-brain barrier or increased water content in the tissue simply cannot reliably detect the effects of treatment on the tumor. 11 C-methionine PET may provide sufficient discrimination between active tumor and brain to help determine responsiveness, but this parameter is also dependent on the relative amount of microvascular density [8,12]. Longitudinal studies in patients with high-grade oligodendrogliomas may reveal different parameters than patients with high-grade astrocytomas.…”