Unexpected detection of melanoma brain metastasis by PET with iodine-124 βCIT

To study the potential impact of iodine-124-β-carbomethoxy-3β(4- iodophenyl)tropane (I-124 βCIT) in Parkinson disease, a I-124 βCIT-PET scan was performed in 30-year-old man with suspected early Parkinson disease. The scan showed normal striatum uptake together with a focal spot in the left parietal cortex. The subsequent magnetic resonance imaging of the brain revealed a corresponding nodular lesion, presumably representing a metastasis. After clinical and diagnostic evaluation, a malignant metastatic melanoma was discovered. βCIT is a cocaine derivative with a high affinity for dopamine and serotonin transporters mainly used to image the density of the dopamine reuptake transporter. In fact the role of I-123 βCIT is typically represented by Parkinsonian syndromes of uncertain classification. The iodine-124 βCIT uptake is a marker of dopamine transporters density, and the presence of focal uptake corresponding to a lesion on magnetic resonance images suggests a specific binding in this case of melanoma brain metastasis. © 2009 Lippincott Williams & Wilkins, Inc.