A Comparative Study on the Uptake and Incorporation of Radiolabeled Methionine, Choline and Fluorodeoxyglucose in Human Astrocytoma

11C-l-Methionine Positron Emission Tomography in the Clinical Management of Cerebral Gliomas

“…Incorporation of 3 H-Met in human brain-14 astrocytomaYIII cell line into protein, RNA, DNA, and lipids was reported by Narayanan et al [89]; kinetic studies showed that maximum incorporation into protein was at 2 h (55%) followed by DNA (11%), RNA (5.8%), and lipids (2.6%) at 4 h of incubation in growth medium containing 1 mCi of 3 H-Met. These observations indicate that in glioma cells, considerable amount of methionine could be utilized for non-protein synthesis; estimation of the rate of protein synthesis from MET uptake must take this into account.…”

11C-Methionine PET for Grading and Prognostication in Gliomas: A Comparison Study with 18F-FDG PET and Contrast Enhancement on MRI

“…The difference in their prognostic value in contrast-enhanced and unenhanced lesions, respectively, highlights their complementary nature and supports our clinical practice of more than a decade of obtaining scans using both 11 C-MET PET and 18 F-FDG PET in patients with suspected gliomas referred to us for evaluation. Our approach of scanning patients with both tracers on the same day is a feasible one that has been used by others and is convenient for the patients (12,17).…”

“…However, 18 F-FDG has high uptake in normal brain cortex and low uptake in LGGs, limiting its usefulness in tumor visualization, delineation, and treatment planning (7,10). On the other hand, L-[methyl-11 C]-methionine ( 11 C-MET) is an amino acid tracer found to be useful in oncologic applications (11,12). 11 C-MET has a high degree of uptake in neoplastic tissue due to its role in protein synthesis (11,12) and in transamination and transmethylation reactions (13) and increased use of amino acids for energy production and as precursors of nonproteins such as DNA, RNA, and lipids (12,14,15).…”

“…On the other hand, L-[methyl-11 C]-methionine ( 11 C-MET) is an amino acid tracer found to be useful in oncologic applications (11,12). 11 C-MET has a high degree of uptake in neoplastic tissue due to its role in protein synthesis (11,12) and in transamination and transmethylation reactions (13) and increased use of amino acids for energy production and as precursors of nonproteins such as DNA, RNA, and lipids (12,14,15). 11 C-MET has an advantage for imaging gliomas because, unlike 18 F-FDG, it has low normal cortical uptake and high uptake in LGGs, enabling tumor visualization and treatment planning (16,17).…”

Metabolic Assessment of Gliomas Using11C-Methionine, [18F] Fluorodeoxyglucose, and11C-Choline Positron-Emission Tomography

“…22 A T/N ratio more than 2.0 means that the tumor SUV is clearly higher than that of the normal frontal cortex; therefore, the tumor is more easily visualized when the T/N ratio increases beyond 2.0. The T/N ratio of FDG was more than 2.0 in 13.7% of all gliomas.…”