18f-fdg pet/ct usefulness vs tc99m-tetrofosmin in the assessment of malignant brain gliomas: report of two cases

gliomas account for almost 80% of primary malignant brain tumors in adults. magnetic resonance imaging (mri) is still the gold standard for diagnosis of brain tumors and brain 99mtc-tetrofosmin single photon emission computed tomography (99mtc-tetrofosmin-spect) has been established as a useful tool for their evaluation. fluorine-18–2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (18f-fdg pet/ct) provides non-invasive information for staging, clinical assessment and prognosis of glial tumors. we report 2 cases of patients with brain lesions described on mri suspected for malignancy, however 99mtc-tetrofosmin-spect that didn’t show any lesion, 18f-fdg pet/ct revealed radiotracer uptake that supported the hypothesis of malignant gliomas, confirmed later by biopsy. our cases confirm 18f-fdg pet/ctmay be useful for differentiating common enhancing malignant brain tumors and is recommended when differential diagnoses are difficult to narrow using mri and 99mtc-tetrofosmin-spect. 18f-fdg pet/ct can be used to characterize their aggressiveness and to detect a more feasible site for a stereotaxic biopsy. it yields supplementary non-invasive information to conventional imaging useful in the clinical decision-making.