RT Journal Article SR Electronic T1 Reduction of SERT binding in Ecstasy users: Reproducibility of PET studies JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 109P OP 109P VO 48 IS supplement 2 A1 Vranesic, Melin A1 Szabo, Zsolt A1 Varga, Jozsef A1 Ricaurte, George A1 McCann, Una YR 2007 UL http://jnm.snmjournals.org/content/48/supplement_2/109P.1.abstract AB 368 Objectives: Carbon-11-labeled-McN-5652 and Carbon-11-labeled-DASB have both recently been highlighted as tracers which detect reduction of the serotonin transporter (SERT) in ecstasy users. This finding has been confirmed by different image processing techniques applied to identical datasets but not to different study populations. We tested the control-user differences of the binding parameters between tracers as well as studies for reproducibility. Methods: To test between-tracer reproducibility, PET studies were obtained with both MCN and DASB in 42 subjects (19 controls, 23 users). To test between-study reproducibility, PET studies with DASB obtained in the same 42 subjects were compared to PET studies obtained in a new set of 32 subjects (16 controls, 16 users). Using compartmental modeling the total tissue distribution volume (DV) was calculated. Correction for nonspecific binding was achieved both by subtracting the cerebellar DV from the regional DV (=DVspec) and by dividing regional DV by cerebellar DV (=DVR). Reduction of binding was calculated from the percent difference between controls and users. Reproducibility was tested by rank correlation, linear correlation, and by factor analysis. Results: Between tracer reproducibility (r) of DV, DVspec and DVR was 0.481, 0.910 and 0.522, respectively. The between study reproducibility (r) of the same three parameters was 0.786, 0.924, and 0.806. Factor analysis showed that 87% of variance can be ascribed to two factors. The reductions of DVspec for both comparisons and both tracers showed high loads on factor 1, while reductions of DVR showed high loads on factor 2. The factorial assignment of DV reductions was less consistent. Conclusions: The results indicate outstanding between-tracer as well as between-study reproducibility of DVspec and excellent between study reproducibility of DV and DVR. These results may assist design and interpretation of PET studies of the SERT in the future.