Development and Clinical Application of [11C]Verapamil-PET

Development and Clinical Application of [11C]Verapamil-PET, a Surrogate Marker on P-glycoprotein Expression

The major hypothesis explaining drug resistance is overexpression of p-glycoprotein at the target lesion. Based on several studies, p-glycoprotein (P-gp) has an important role in neurologic diseases, especially in drug resistant epilepsy. But there is no surrogate marker that can quantify the expression of P-gp because of the difficulty in measuring substances in the neurologic system and the lack of clinical trials. Here, the investigators use a novel non-invasive [11C] -verapamil Brain PET and SPAM analytic method as a surrogate marker for quantifying the expression of p-glycoprotein.

A pilot study on healthy volunteers and a case-control study on patients with drug resistant epilepsy and drug sensitive epilepsy is performed. The investigators compare the whole brain SUV in each group (normal control, drug resistant epilepsy, drug sensitive epilepsy) and the asymmetry by the standardized uptake value(SUV) of ipsilateral areas and contralateral areas. [11C] -verapamil PET will be used as a surrogate marker of P-gp expression in patients with epilepsy, and will be an important prognostic factor of individualized drug therapy. Also, it can be used as a biomarker in checking of the drug efficacy of novel medications. Furthermore, by localizing epileptogenic zones for patients, [11C] -verapamil PET could contribute in improving the prognosis of surgical treatment in drug resistant epilepsy.

Normal controls take a [11C] -verapamil PET scan. While P-gp inhibitor (Cyclosporin A, 2.5mg/kg/hr during 2hours, intravenous) is infused, PET scans were done using [11C] -verapamil, a substrate of P-gp.

Patients with drug-resistant epilepsy take a [11C] -verapamil PET scan. While P-gp inhibitor (Cyclosporin A, 2.5mg/kg/hr during 2hours, intravenous) is infused, PET scans were done using [11C] -verapamil, a substrate of P-gp.

Patients with drug-sensitive epilepsy take a [11C] -verapamil PET scan. While P-gp inhibitor (Cyclosporin A, 2.5mg/kg/hr during 2hours, intravenous) is infused, PET scans were done using [11C] -verapamil, a substrate of P-gp.

While P-gp inhibitor (Cyclosporin A, 2.5mg/kg/hr during 2hours, intravenous) is infused, PET scans were done using [11C] -verapamil, a substrate of P-gp.

Measured Asymmetric index[(SUV in Right regions - SUV in Left regions)/(SUV in Right regions+ SUV in left regions)] in all three groups

Inclusion Criteria: Healthy controls ( age range 20-45 years) Patient age (> 15), diagnose as epilepsy Exclusion Criteria: Subjects who take medicines that affect on the function of p-glycoproteins Pregnancy or subject who feed the breast milk Subjects who had severe renal disease or liver disease Subjects who need treated by immunosuppressant or take immunosuppressant