Multicenter Semiquantitative Evaluation of (123)I-FP-CIT Brain SPECT

The aims of this study were: (1) to cross-compare data from semiquantitative, software-assisted, and phantom-corrected evaluations of (123)I-ioflupane [(123)I]N-ω-fluoropropyl-2β-carbomethoxy-3β-{4-iodophenyl}nortropane FP-CIT brain single-photon emission computed tomography (SPECT) acquired in three centers; (2) to assess the accuracy of semiquantitative evaluation; and (3) to identify the threshold with the best accuracy, sensitivity, and specificity in patients with suspected Parkinsonian Syndrome.

Two-hundred-twenty patients, acquired in three centers, were included. All of them underwent (123)I-FP-CIT brain SPECT. All examinations were analyzed with the freely available software, BasGan, and semiquantitative data were used to predict disease. Analysis was based on the values from the most deteriorated putamen and caudate, normalized for age, and corrected by anthropomorphic phantom data. Receiver operating characteristic (ROC) analysis was performed and areas under the curve (AUC) were estimated.

Analysis showed high AUCs (.880, .866, .920, and .882 for each center and multicenter setting). Best thresholds were 1.53 and 1.56 for putamen and caudate, respectively. Thresholds of putamen data showed sensitivity and specificity of 86% and 89%, respectively, in the multicenter setting. Neither sensibility nor specificity showed significant differences among centers.

A unique, accurate threshold for all centers, with high sensitivity and specificity was identified. Semiquantitative assessment of (123)I-FP-CIT brain SPECT among different centers resulted reliable, accurate, and potentially useful in clinical trials.