PW01-230 - [¹⁸F]Fallypride Pet Measurement Of Striatal And Extrastriatal Dopamine D_2/3 Receptor Availability In Patients With Alcohol Use Disorder

Abstract

Aim

Dopaminergic pathways are implicated in motivational aspects of substance use disorders, and might contribute to withdrawal phenomena, as well as an increased long-term risk of relapse. Molecular imaging with positron emission tomography (PET) revealed reductions in the availability of binding sites for D_2/3receptor ligands in striatum of withdrawn abusers of cocaine; corresponding results in alcoholics have been inconsistent so far. In the present study, we used the D_2/3ligand [¹⁸F]fallypride to investigate dynamic changes in receptor availability in the striatum of patients with alcohol use disorder before and after undergoing a detoxification protocol.

Methods

18 male patients (mean age 44±5.3y) with alcohol use disorder were recruited and scanned with 180MBq [¹⁸F]fallypride upon hospital admission, and again 1-2 weeks later after detoxification. The control group consisted of 10 age-matched healthy volunteers. PET acquisition time was 180min, consisting of 39 frames of increasing duration. Within each group binding potentials (BP_ND) were calculated in the striatum using the cerebellum as reference.

Results

In the patients, the mean BP_ND in whole striatum was 17.2±4.2 at baseline, with a trend towards a decline at follow-up. In addition there were inverse correlations of BP_NDwith age (r-0.45) and with daily alcohol consumption (r-0.2). The age-dependence of BP_NDwas less pronounced in healthy controls. However, mean striatal BP_NDwas only slightly lower in the patient group. No pronounced group differences were evident for extrastriatal [¹⁸F]fallypride binding.

Conclusions

Regressions with age suggest an accelerated loss of dopamine D_2/3 receptors in the striatum of subjects with alcohol use disorder.