Striatal dopaminergic D-2 receptor density measured by [I-123]lodobenzamide SPECT in the prediction of treatment outcome of alcohol-dependent patients

Objective: The authors' goal was to study striatal dopaminergic dopamine 2 (D-2) receptors as a biological marker of early relapse in detoxified alcoh olic patients by using [I-123]iodobenzamide ([I-123]IBZM) single photon emi ssion computed tomography (SPECT). Method: The authors performed [I-123]IBZ M SPECT on 21 alcohol-dependent inpatients during detoxification and on nin e healthy volunteers, using the ratios of basal ganglia to occipital lobes for SPECT quantification. Depending on treatment outcome 3 months after hos pital discharge, patients were determined to be relapsers or nonrelapsers. Results: Alcohol-dependent subjects with early relapse (within 3 months aft er hospital discharge) showed a higher uptake of [I-123]IBZM in the basal g anglia during detoxification (mean ratio=1.83, SD=0.9) than patients who di d not have early relapse (mean ratio=1.69, SD=0.11). Conclusions: These res ults suggest that low levels of dopamine, or an increased density of free s triatal dopaminergic D-2 receptors, could be related to early relapse in al cohol-dependent patients. Therefore, [I-123]IBZM SPECT could become a biolo gical marker of vulnerability to relapse for alcoholic patients in recovery .