Extrastriatal uptake related to dopaminergic dysfunction on 99mTc-TRODAT-1 brain SPECT in patient with atypical meningioma.

Abstract

Extrastriatal accumulation on technetium-99m-([2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]- ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)])(^99mTc)-TRODAT-1 is unexpected during nuclear medicine nigrostriatal pathway examinations on ^99mTc-TRODAT-1 brain single photon emission computed tomography (SPECT). An 86-year-old female with a history of right hemiparesis, speech expressive difficulties, unstable gait, and bradykinesia on right side was reported. Technetium-99m -TRODAT-1 dopamine transporter SPECT revealed an incidental extrastriatal accumulation of radiotracer in the left anterior frontal region, accompanied by a photopenic area which resulted in the displacement of the left striatum with decreased dopaminergic neuronal function. The brain magnetic resonance imaging (MRI) revealed an invasive meningioma corresponding to the extrastriatal uptake on SPECT, accompanied by edema and mass effect. The patient received surgery and the histopathological results confirmed the diagnosis of atypical meningioma.This study emphasizes the importance of understanding the underlying causes of extrastriatal uptake from ^99mTc-TRODAT-1 brain SPECT, which may indicate an invasive brain tumor.