[Phase 2 clinical study of 123I-IBF, a dopamine D2 receptor imaging agent, to evaluate clinical efficacy and safety in Parkinson's disease and Parkinson syndromes].
A Phase 2 multicenter trial of 123I-IBF, (S)-5-iodo-7-N-[(1-ethyl-2- pyrrolidinyl)methyl]carboxamido-2,3-dihydrobenzofuran, was conducted to evaluate its clinical efficacy and safety in 158 patients with Parkinson's disease (PD) or Parkinson syndromes (PS). SPECT data were acquired at two hours (2H-SPECT), after intravenous injection of 123I-IBF (167 MBq). Additional SPECT scan at three hours (3H-SPECT) and dynamic SPECT scan at most until one hour were performed when possible. No severe side effects due to 123I-IBF injection were observed. The sensitivity, specificity and accuracy for discriminating PS from PD using the striatal specific binding count-to-frontal cortex count ratio (St/Fc-1) in 3H-SPECT were 72.7%, 81.0% and 78.1% in 64 clinically definite cases (i.e., typical cases), respectively. The putamen-to-caudate ratios were significantly lower in striatonigral degeneration compared with those in PD. The contralateral-to-ipsilateral ratios against the symptomatic side of tremor and/or rigidity in the patients with PD (Hoehn & Yahr I) were significantly higher than the left-to-right ratios in the normal controls. St/Fc-1 in 3H-SPECT was significantly lower in the patients showing a poor response to levodopa than in those showing a good response. The dopamine D2 receptor binding potential (k3/k4), obtained by dynamic SPECT based on compartment model analysis, correlated well with the striatal specific binding count-to-occipital cortex count ratio. These results suggest that 123I-IBF is a promising agent for differential diagnosis and pathophysiological evaluation of PD and PS.
Torizuka
K
K
Kyoto University.
Mizuno
Y
Y
Kubo
A
A
Konishi
J
J
Yonekura
Y
Y
Hatazawa
J
J
Momose
T
T
Murata
M
M
Amano
T
T
Fukuyama
H
H
Kuwabara
Y
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001572:Benzofurans / Q000493:pharmacokinetics; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon
D001572:Benzofurans; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2