Incidental detection of probable meningioma in brain scintigraphy using 99mTc-TRODAT-1.

An 84-year-old woman underwent a dopamine transporter (DAT) study to investigate a non-levodopa-responsive parkinsonism. A SPECT brain scan was conducted four hours after intravenous administration of 1110 MBq (megabecquerels) equivalent to 30 mCi (millicuries) of 99mTc–TRODAT-1. The study revealed a significant uptake deficit of radiopharmaceuticals in the striatum. The semi-quantitative analysis of density of DAT showed radiopharmaceutical uptake indexes of 0.40 and 0.55 in the right and left side of the striatum, respectively. In addition, the right:left ratio was 0.73. As well, scintigraphy images showed intense uptake of the radiopharmaceutical in the extra-axial left frontal lobe consistent with meningioma in a subsequent magnetic resonance imaging (MRI) study (Figure). The anatomical MRI sequences showed an intensely enhancing extra-axial mass in the left frontal lobe measuring about 2.8 x 4.1 x 4.1 cm with a broad dural base and heterogeneous