How is F18 produced?

1.1. Fluorine-18 is produced with a cyclotron primarily by proton (1H) irradiation of 18O, a stable naturally occurring isotope of oxygen. When the target is liquid H218O, an aqueous solution of 18F-fluoride ion is obtained; when the target is 18O2 gas, 18F–F2 gas is obtained.

What are the steps in the production of F 18 from a cyclotron?

In order to emit positron, fluorine-18 (18F) isotope is prepared from water enriched with the 18O isotope using high energy protons by a cyclotron. A cyclotron is a particle accelerator. These particles are then focused onto a target O18 and the bombardment causes the production of the desired radioisotope i.e. F18.

What is the product of positron emission from F 18?

Fluorine F 18 decays by positron ,(β+) emission and has a half-life of 109.7 minutes. The principal photons useful for diagnostic imaging are the 511 keV gamma photons, resulting from the interaction of the emitted positron with an electron (Table 1).

What is the mechanism of uptake for 18F FDG?

18F-FDG enters the cell by facilitated diffusion or secondary active transport. After being phosphorylated by hexokinase, FDG-6-phosphate (FDG-6-PO4) cannot participate in the Krebs cycle or exit the cell, resulting in increased signal intensity from metabolically active cells.

What is the precursor to 18 F FDG?

Mannose triflate is used as a precursor, Kryptofix 222 as a catalyst and acetonitrile as a solvent. The steps to synthesis of 18 F-FDG are completed in an automated synthesis box, after production of 18 F in a 18 O (p,n) 18 F – cyclotron reaction and are listed below in order (Fowler, 2002; Yu, 2006).

How is 18 F FDG made in a cyclotron?

[ 18 F]FDG was first synthesized via electrophilic fluorination with [ 18 F]F 2. Subsequently, a “nucleophilic synthesis” was devised with the same radioisotope. As with all radioactive 18 F-labeled radioligands, the 18 F must be made initially as the fluoride anion in a cyclotron.

How long does it take to make 18 F FDG?

In 1986 Hamacher et al developed a new method using nucleophilic displacement, which had a higher yield (>50%) and shorter production time of 50 mins (Mettler, 2012; Yu, 2006). Since 18 F has a relatively short half-life (110mins) production and supply of 18 F-FDG is usually limited to areas near a cyclotron.

Where can I find 18 F FDG tracer?

Since 18 F has a relatively short half-life (110mins) production and supply of 18 F-FDG is usually limited to areas near a cyclotron. The manufacture of the tracer also requires an automated synthesis box (Saha, 2010). In the first synthesis of 18 F-FDG a 20 Ne (d,α) 18 F reaction was used to form 18 F-F -2.