Quantification of Dopamine Transporter Binding Using [¹⁸F]FP-β-CIT and Positron Emission Tomography

Abstract

The purpose of this study was to compare different kinetic and semi-quantitative methods for analysing human [18 F]FP-b-CIT studies: plasma input models, simplified (SRTM) and full (FRTM) reference tissue models, standard uptake values (SUV) and SUV ratios (SUVr). Both simulations and clinical evaluations were performed to determine the effects of noise, scan duration and blood volume on Akaike model selection, and on precision and accuracy of estimated parameters. For typical noise levels (COVB2.5%) and scan durations ( < 90 mins), simulations provided poor fits (Akaike criterion) in case of reversible plasma input models showing a relatively high number of outliers compared with the two-tissue irreversible model. Reference tissue models provided more reliable fits, which were nearly independent of noise and scan duration. For clinical data, two tissue irreversible and reversible plasma input models fitted striatum curves equally well (Akaike criterion). BP with plasma input models were less precise and contained more outliers than BP obtained with SRTM or FRTM. Among all methods tested, SRTM showed the highest contrast between patients and controls. When differentiating between patients and controls, SUVr performed almost equally well as SRTM, although contrast between striatum and background was lower. In conclusion, SRTM provided BP estimates with the highest precision and accuracy. Moreover, SRTM provided good contrast between patients and controls, and between striatum and background. SRTM is therefore the method of choice for quantitative [18 F]FP-b-CIT studies. SUVr might be an alternative for larger clinical trials.

Segmentation-Based MR Attenuation Correction Including Bones Also Affects Quantitation in Brain Studies: An Initial Result of 18F-FP-CIT PET/MR for Patients with Parkinsonism

“…For quantitative analysis, static PET images can be used when 18 F-FP-CIT reaches equilibrium binding in the brain, because a simple ratio of regional counts is proportional to binding potential (20,21). However, it remains unclear whether quantitative 18 F-FP-CIT binding potential acquired from PET/MR is concordant with that from PET/CT because of the differences in AC methods and hardware.…”

Clinical Significance of F-18 FP-CIT Dual Time Point PET Imaging in Idiopathic Parkinson’s Disease

“…Specific uptake of F-18 FP-CIT of the normal striatum reaches a peak equilibrium state at 90 min or more after injection [5,6]. In Parkinson patients, however, it is thought that the time required to reach this peak equilibrium state is shortened [5], and F-18 FP-CIT activity is likely to washout sooner.…”

“…The authours obtained early images 90 min after injection because several studies showed that specific uptake into the corpus striatum peaks after at least 90 min post-administration in healthy controls [5,6]. However, not all patients achieve a peak equilibrium state at 90-120 min, and pseudoeuilibrium is estimated to occur more than 2 h later.…”

“…For clinical use of F-18 FP-CIT in PD, many researchers have studied the pharmacokinetics of the radiotracer and image acquisition times [5][6][7]. The specific striatal uptake of F-18 FP-CIT was found to reach its maximal value at 90-120 min postinjection in normal subjects on dynamic analysis [5,6].…”

“…The specific striatal uptake of F-18 FP-CIT was found to reach its maximal value at 90-120 min postinjection in normal subjects on dynamic analysis [5,6]. However, Kim [8] insisted more research was needed for choosing the image acquisition time because the specific striatal uptake of F-18 FP-CIT was not reached in this time in some of patients but could reach a pseudoequilibrium state after 2 h like I-123 FP-CIT.…”