Biodistribution and dosimetry of [123I]iodo-PK 11195: a potential agent for SPET imaging of the peripheral benzodiazepine receptor.
Eur J Nucl Med
; 27(9): 1326-33, 2000 Sep.
Article
em En
| MEDLINE
| ID: mdl-11007514
ABSTRACT
The highest concentrations of the peripheral benzodiazepine receptor (PBR) are found in the kidneys and heart. In addition, the PBR has been reported to reflect neuro-inflammatory damage by co-localisation with activated microglia. PK 11195 is a high-affinity ligand for the PBR. The aim of this study was to investigate in humans the biodistribution and dosimetry of [123I]iodoPK 11195, a potential single-photon emission tomography tracer for the PBR. Five healthy volunteers were injected with 112 MBq of [123I]iodo-PK 11195. Sequential whole-body scans were performed up to 72 h post injection. Multiple blood samples were taken, and urine was collected to measure the fraction voided by the renal system. Decay-corrected regions of interest of the whole-body images were analysed, and geometric mean count rates were used to determine organ activity. Organ absorbed doses and effective dose were calculated using the MIRD method. [123I]iodo-PK 11195 was rapidly cleared from the blood, mainly by the hepatobiliary system. Approximately 22% was voided in urine after 48 h. Average organ residence times were 0.74, 0.44 and 0.29 h for the liver, upper large intestine and lower large intestine, respectively. The testes received the highest dose, 109.4 microGy/MBq. All other organs investigated received doses of less than 50 microGy/MBq. The effective dose was 40.3 microSv/MBq. In conclusion, [123I]iodo-PK 11195 is a suitable agent for the visualisation of the PBR and indirectly for the imaging of neuro-inflammatory lesions. Taking into account the radiation burden of 7.46 mSv following an administration of 185 MBq, a [123I]iodo-PK 11195 investigation has to be considered an ICRP risk category IIb investigation.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Radiometria
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Tomografia Computadorizada de Emissão de Fóton Único
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Receptores de GABA-A
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Radioisótopos do Iodo
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Isoquinolinas
Limite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Eur J Nucl Med
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Holanda