@jeffmarc The reason why Choline C-11 (Carbon-11) isn’t used in but one place in the U.S. - Mayo Clinic Rochester - is more about logistics (& perhaps financials) than anything else.

The half-life of Choline C-11 is very short, about 20 minutes, which means it has to be used very quickly after its generation. This rapid decay makes its use limited elsewhere. (Plus, I’ve read that there are still patents related to Choline C-11 for its use in medical imaging.)

If you recall, this was the same challenge when PSMA was first FDA-approved in late 2020. The clinical trials using Gallium68 (68Ga-PSMA-11 - later trade-named Illuccix) were all done at UCLA and UCSF. With the half-life of Gallium68 being just 58 minutes, there was no way to access it unless you travelled to either of those universities.

These days there are a number of “kits” that are used to generate not only Gallium68 for PSMA PET scans, but also F18-DCFPyL (trade name: PYLARIFY®) and F-18-Flotufolastat (trade name: Posluma®). So, if a Facility has the proper ‘kit’ they can generate the isotope on-site.

Mayo Clinic had been using Choline C11 in clinical trials for almost a decade before it was FDA-approved for prostate cancer diagnosis in 2012. So, they’re the recognized experts in its use, the only one that uses it, and probably has a vested (financial) interest in its continued use.

It’s said that the Choline C11 PET scan is on-par with the Axumin PET scan.
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Many PET scans have been developed over the past 25 years to diagnose prostate cancer:

> F18-FDG (Fluoro-2-Deoxyglucose) PET/CT: FDA approved in August 1999

> F18-NaF (Sodium Fluoride) PET/CT: FDA approved in February 2011

> Choline C11 (Carbon 11) PET/CT: FDA approved in September 2012

> F18-Fluciclovine PET/CT: (trade name: Axumin®): FDA approved in May 2016

> 68Ga-PSMA-11 (Gallium68) PSMA PET: (trade name: Illuccix®): FDA Approved in December 2020

> F18-DCFPyL (Piflufolastat) PSMA PET: (trade name: PYLARIFY®): FDA approved in May 2021

> F-18-Flotufolastat PSMA PET: (trade name: Posluma®): FDA approved in June 2023.

More are coming…….
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