Development of a non-radiometric method for measuring the arterial input function of a C-11-labeled PET radiotracer
Cheryl L. Morse; Robert B. Innis; Aneta Kowalski; Sami S. Zoghbi; H. Umesha Shetty; Victor W. Pike; Jussi Hirvonen
Development of a non-radiometric method for measuring the arterial input function of a C-11-labeled PET radiotracer
Cheryl L. Morse
Robert B. Innis
Aneta Kowalski
Sami S. Zoghbi
H. Umesha Shetty
Victor W. Pike
Jussi Hirvonen
NATURE RESEARCH
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2021042826973
https://urn.fi/URN:NBN:fi-fe2021042826973
Tiivistelmä
Positron emission tomography (PET) uses radiotracers to quantify important biochemical parameters in human subjects. A radiotracer arterial input function (AIF) is often essential for converting brain PET data into robust output measures. For radiotracers labeled with carbon-11 (t(1/2)=20.4 min), AIF is routinely determined with radio-HPLC of blood sampled frequently during the PET experiment. There has been no alternative to this logistically demanding method, neither for regular use nor validation. A C-11-labeled tracer is always accompanied by a large excess of non-radioactive tracer known as carrier. In principle, AIF might be obtained by measuring the molar activity (A(m); ratio of radioactivity to total mass; Bq/mol) of a radiotracer dose and the time-course of carrier concentration in plasma after radiotracer injection. Here, we implement this principle in a new method for determining AIF, as shown by using [C-11]PBR28 as a representative tracer. The method uses liquid chromatography-tandem mass spectrometry for measuring radiotracer A(m) and then the carrier in plasma sampled regularly over the course of a PET experiment. A(m) and AIF were determined radiometrically for comparison. The new non-radiometric method is not constrained by the short half-life of carbon-11 and is an attractive alternative to conventional AIF measurement.
Kokoelmat
- Rinnakkaistallenteet [19206]