Clinical correlation of the binding potential with 123I-FP-CIT in de novo idiopathic Parkinson's disease patients

Eur J Nucl Med Mol Imaging. 2008 Dec;35(12):2220-6. doi: 10.1007/s00259-008-0872-4. Epub 2008 Jul 23.


Purpose: The aim of this study was to evaluate the accuracy of different single-photon emission computed tomography (SPECT) reconstruction techniques in measuring striatal N-omega-fluoropropyl-2beta-carbomethoxy-3beta-4-[(123)I]iodophenyl-nortropane ((123)I-FP-CIT) binding in de novo Parkinson's disease (PD) patients, in order to find a correlation with clinical scales of disease severity in the initial phases of disease.

Methods: Thirty-six de novo PD patients underwent (123)I-FP-CIT SPECT and MRI scan. SPECT data were reconstructed with filtered back projection (FBP), with an iterative algorithm (ordered subset expected maximization, OSEM) and with a method previously developed in our institution, called least-squares (LS) method. The ratio of specific to non-specific striatal (123)I-FP-CIT binding (binding potential, BP) was used as the outcome measure with all the reconstruction methods (BP(FBP), BP(OSEM), BP(LS)).

Results: The range of values of striatal BP(LS) was significantly greater than BP(FBP) and BP(OSEM). For all striatal regions, estimates of BP(FBP) correlated well with BP(OSEM) (r = 0.84) and with BP(LS) (r = 0.64); BP(OSEM) correlated significantly with BP(LS) (r = 0.76). A good correlation was found between putaminal BP(LS) and Hoen and Yahr, Unified PD Rating Scale (UPDRS) and lateralized UPDRS motor scores (r = -0.46, r = -0.42, r = -0.39, respectively). Neither putaminal BP(FBP) nor putaminal BP(OSEM) correlated with any of these motor scores.

Conclusions: In de novo PD patients, (123)I-FP-CIT BP values derived from FBP and OSEM reconstruction techniques do not permit to differentiate PD severity. The LS method instead finds a correlation between striatal BP and disease severity scores. The results of this study support the use of (123)I-FP-CIT BP values estimated with the LS method as a biomarker of PD severity.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Corpus Striatum / metabolism
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Motor Activity
  • Parkinson Disease / diagnostic imaging
  • Parkinson Disease / metabolism*
  • Parkinson Disease / pathology
  • Parkinson Disease / physiopathology
  • Tomography, Emission-Computed, Single-Photon
  • Tropanes / metabolism*


  • Tropanes
  • 2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane