Display Settings:


Send to:

Choose Destination
See comment in PubMed Commons below
Nucl Med Biol. 2011 Oct;38(7):987-95. doi: 10.1016/j.nucmedbio.2011.04.003. Epub 2011 Jun 22.

Evaluation of F-18-labeled 5-iodocytidine (18F-FIAC) as a new potential positron emission tomography probe for herpes simplex virus type 1 thymidine kinase imaging.

Author information

  • 1Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 11221, Taiwan.



Herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene in combination with radiolabeled nucleoside substrates is the most widely used reporter system. This study characterized 1-(2'-deoxy-2'-[(18)F]fluoro-β-D-arabinofuranosyl)-5-iodocytosine ((18)F-FIAC) as a new potential positron emission tomography (PET) probe for HSV1-tk gene imaging and compared it with 2'-deoxy-2'-[(18)F]fluoro-5-iodo-1-β-D-arabinofuranosyluracil ((18)F-FIAU) and 2'-deoxy-2'-[(18)F]fluoro-5-ethyl-1-β-D-arabinofuranosyluracil((18)F-FEAU) (thymidine analogues) in an NG4TL4-WT/STK sarcoma-bearing mouse model.


A cellular uptake assay, biodistribution study, radioactive metabolites assay and microPET imaging of NG4TL4-WT/STK tumor-bearing mice post administration of (18)F-FIAC, (18)F-FIAU and (18)F-FEAU were conducted to characterize the biological properties of these tracers.


Highly specific uptake of (18)F-FIAC, (18)F-FIAU and (18)F-FEAU in tk-transfected [tk(+)] cells was observed. The tk(+)-to-tk(-) cellular uptake ratio after a 2-h incubation was 66.6±25.1, 76.3±18.2 and 247.2±37.2, respectively. In biodistribution studies, (18)F-FIAC showed significant tk(+) tumor specificity (12.6; expressed as the tk(+)-to-tk(-) tumor uptake ratio at 2 h postinjection) comparable with (18)F-FIAU (15.8) but lower than (18)F-FEAU (48.0). The results of microPET imaging also revealed the highly specific accumulation of these three radioprobes in the NG4TL4-tk(+) tumor.


Our findings suggested that the cytidine analogue (18)F-FIAC is a new potential PET probe for the imaging of HSV1-tk gene expression. (18)F-FIAC may be regarded as the prodrug of (18)F-FIAU in vivo.

Copyright © 2011 Elsevier Inc. All rights reserved.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk