Positron emission tomography imaging in gliomas

Glioma, the most frequent primary brain tumor in adults, is a highly infiltrative tumor exhibiting resistance to most treatments and associated with short survival of patients. Positron emission tomography (PET) imaging using various tracers takes advantage of the increased metabolic rate of neoplastic cells, in order to detect tumors and validate the treatment response. The most frequently used PET tracer, the (18)F-fluorodeoxyglucose (FDG), is useful during the initial and follow-up assessment of patients with gliomas because it can assist in the selection of the initial biopsy site and to assess early response to a given therapeutic intervention. Furthermore, when there is tumor re-growth after an initial remission, FDG-PET can differentiate between true tumor recurrence versus necrosis from radiation therapy. Newly developed PET tracers may exhibit better sensitivity than FDG to diagnose primary brain tumors, but may occasionally produce false positive results in various conditions. In any event, PET is a useful tool in patients with central nervous system cancer during both initial assessment and follow-up