Format

Send to

Choose Destination
See comment in PubMed Commons below
Nucl Med Commun. 2007 Oct;28(10):823-8.

Intra-individual comparison of the human biodistribution and dosimetry of the D and L isomers of 2-[123I]iodo-phenylalanine.

Author information

1
BEFY, Radiopharmaceutical Chemistry, Vrije Universiteit Brussels, Laarbeeklaan 103, 1090 Brussels, Belgium. matthias.bauwens@vub.ac.be

Abstract

PURPOSE:

Several authors have shown in animal studies that D-enantiomeric amino acid analogues can have better tumour imaging properties compared to their L-analogues. In our group, the D and L isomers of 2-[I]iodo-phenylalanine were identified as tumour-specific tracers in rat and mouse tumour models, with an advantage for the D-isomer. Here we compare, intra-individually, the normal biodistribution and dosimetry of both tracers in healthy human subjects.

METHODS:

Five male volunteers received both the L- and D-enantiomers, ranging from 84 to 114 MBq, with a 1 week interval between the tracers, allowing intra-individual comparison. Whole-body scans were performed and blood and urine samples were collected and analysed up to 24 h. Dosimetry was calculated using OLINDA 1.0 software.

RESULTS:

The biodistributions of the tracers are comparable as both show a moderate uptake in heart and the liver, a marked uptake in muscle tissue and clearance via the renal system. However, due to faster clearance, from 2.5 h, the uptake of the D-enantiomer was significantly lower compared to the L-isomer in all organs. The radiation dose estimations showed an effective dose of, respectively, 0.0120+/-0.0020 mSv x Bq(-1) and 0.0106+/-0.0038 mSv x Bq(-1) for 2-123I-L-Phe and 2-123I-D-Phe (P=0.18). In both cases the organ receiving the highest dose was the bladder wall.

CONCLUSION:

Both 2-123I-L-Phe and 2-123I-D-Phe show comparable moderate uptake in all organs. 2-123I-D-Phe is the more promising tracer, as it shows a faster clearance resulting in a lower dose and a lower background, favouring tumour imaging with respect to the tumour/background ratio.

PMID:
17728613
DOI:
10.1097/MNM.0b013e3282e7d731
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wolters Kluwer
    Loading ...
    Support Center