Tumor uptake of L-[methyl-11C]methionine ([11C]Met) was assessed in six patients with brain tumors and three patients with lung cancer using positron emission tomography (PET). In arterial plasma samples taken at 5, 15, 30, and 60 min after injection, a fraction of [11C]Met was measured using high performance liquid chromatography in individual patients. Employing curve fitting, a history of [1...

Abstract AIMS To characterize spatial distributions of 18kDa translocator protein (TSPO) and amino acid uptake as measured through dynamic [11C] (R)-PK11195 [11C]-methionine PET in high-grade glioma. METHOD Twelve patients with newly diagnosed glioma underwent dual studies. binding potential (BPND) maps were generated using simplified reference tissue model grey-matter cerebellar time- activity...

UNLABELLED We evaluated the value of PET using 18F-fluorodeoxyglucose (FDG) and 11C-methionine, individually or in combination, to distinguish malignant from benign tumors and to identify or exclude mediastinal metastases. METHODS Seventeen patients with a tumor in the lung or mediastinum were evaluated with 18F-FDG and 11C-methionine PET. For morphological comparison, we used CT, and all fin...

BACKGROUND Glycine N-methyltransferase is an enzyme overexpressed in some neoplastic tissues. It catalyses the methylation of glycine using S-adenosyl methionine (SAM or AdoMet) as substrate. SAM is involved in a great variety of biochemical processes, including transmethylation reactions. Thus, [11C]SAM could be used to evaluate transmethylation activity in tumours. The only method reported fo...

BACKGROUND Gangliogliomas involving the optic nerve or chiasm are extremely rare tumors, which can be confused radiologically with other neoplasms. α-[N-methyl-11C]-methylaminoisobutyric acid (11C-MeAIB) is a new artificial amino acid positron emission tomography (PET) tracer, which is metabolically more stable in vivo and may be more specific for tumors than 11C-methionine. However, the utilit...

BACKGROUND Tumor to normal tissue ratio (T/N ratio) on 11C-methionine (11C-MET) positron emission tomography/computed tomography (PET/CT) is affected by variable factors. We investigated whether T/N ratio cutoff values corrected according to metabolic tumor volume (MTV) could improve the diagnostic performance of 11C-MET PET/CT for diagnosis of recurrence in patients with metastatic brain tumor...

Existing methods for assessing protein synthetic rates (PSRs) in human skeletal muscle are invasive and do not readily provide information about individual muscle groups. Recent studies in canine skeletal muscle yielded PSRs similar to results of simultaneous stable isotope measurements using L-[1-13C, methyl-2H3]methionine, suggesting that positron-emission tomography (PET) with L-[methyl-11C]...

Tumor cells can be selectively killed by application of s-ligands; high concentrations (20–100 mM) are often required, however, because either diffusion barriers must be passed to reach intracellular sites or the entire s-receptor population should be occupied to induce cell death. We measured receptor occupancies associated with the cytotoxic effect and dose-dependent changes of cellular metab...