Medicina Nuclear e Radioterapia

mGluR5 PET Imaging Using 18F-FPEB in Medically Refractory Epilepsy Patients

Abstract

Mehdi Djekidel, Beata Planeta, Tore Eid, Hitten Zaveri, Irina Goncharova, Keunpoong Lim, David Labaree, Yiyun Huang, Dennis Spencer and Richard E Carson

Introduction: mGluR5 availability in medically refractory epilepsy patients compared to healthy controls (HC) using the PET agent ¹⁸F-FPEB was assessed.

Methods: Five epilepsy patients (mean age: 33.6; SD: 13.04); (4F, 1M) and 8 HC (mean age: 24.4; SD of 4.8); (5 M, 3 F) were studied with a High-Resolution Research Tomography and a bolus/infusion technique. Volume of distribution corrected for plasma free fraction values (V_T/f_p) was determined from equilibrium data in different brain regions including the seizure onset zone (SOZ), which was determined at an epilepsy surgical conference.

Results: A trend towards global decreases in ¹⁸F-FPEB V_T/f_p was noted. Significant decreases were seen in the frontal lobes, and limbic structures: The amygdala, hippocampi, and thalami compared to HC. No significant differences were found between SOZ and a contralateral mirror region.

Conclusion: ¹⁸F-FPEB human imaging of the mGluR5 system in refractory epilepsy showed significant decreases in the frontal lobes and limbic structures.