# Germanium-68

Source: https://nuclide.cc/isotopes/ge-68/  
Nuclide record `ge-68` (Isotope). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

The long-lived parent locked inside a gallium-68 generator. One loaded column can supply a year's worth of PET tracer doses for prostate cancer and neuroendocrine tumour scans, but the generators themselves have been expensive and slow to get.

## Summary

Germanium-68 decays by electron capture with a 270.8-day (about 9-month) half-life, far too long to be imaged usefully itself; its entire clinical role is as the parent bound inside a 68Ge/68Ga generator column, decaying continuously to the 68-minute daughter gallium-68 that is eluted with dilute acid for use in PET tracers such as 68Ga-DOTATATE and 68Ga-PSMA-11. Because the parent's half-life is roughly 5,800 times the daughter's, a single generator loaded with germanium-68 supplies a fairly constant, though slowly declining, stream of gallium-68 for around a year before it needs replacing.

Germanium-68 itself is made almost exclusively by high-energy proton bombardment of a gallium metal target enriched in the stable isotope gallium-69, via the 69Ga(p,2n)68Ge reaction; because commercial-scale generator loadings require tens of gigabecquerels of activity and the reaction needs proton energies of roughly 20-30 MeV over several days of irradiation at high beam current, only a small number of high-energy cyclotron and accelerator facilities worldwide can produce it (an alternative 66Zn(alpha,2n)68Ge route using alpha-particle beams exists but is less commonly used).

That narrow production base is why 68Ge/68Ga generator supply has repeatedly lagged clinical demand: GMP-grade generator lead times ran as long as 18 months in the years before the 2016-2020 approvals of gallium-68 DOTATATE and PSMA-11 PET agents, and a 2017 shortage of germanium feedstock further squeezed availability, prompting the IAEA in 2019-2020 to promote direct cyclotron production of gallium-68 (68Zn(p,n)68Ga) as a way to sidestep the germanium-68 bottleneck altogether rather than solve it. Manufacturers including Eckert & Ziegler subsequently expanded generator manufacturing capacity, and by the mid-2020s most large PET centres have access to either generator- or cyclotron-produced gallium-68, though the underlying germanium-68 production base remains concentrated in a handful of accelerator facilities.

## Fields

- Kind: Isotope
- Status: established
- Last checked: 2026-09-22
- Also known as: 68Ge; Ge-68
- Tags: generator parent; long-lived; supply bottleneck

## Sources

- PMC: good practices for 68Ga radiopharmaceutical production (68Ge production section): https://pmc.ncbi.nlm.nih.gov/articles/PMC9588110/
- Wikipedia: gallium-68 generator (68Ge production routes): https://en.wikipedia.org/wiki/Gallium-68_generator
- IAEA: new CRP on cyclotron-based gallium-68 (2020): https://www.iaea.org/newscenter/news/new-crp-production-of-cyclotron-based-gallium-68-radioisotope-and-related-radiopharmaceuticals-f22073

## Connected records

- isotopes: [Gallium-68](https://nuclide.cc/isotopes/ga-68/)
- drugs: [Gallium-68 DOTATATE (and Cu-64 DOTATATE)](https://nuclide.cc/drugs/ga68-dotatate/), [Gallium-68 gozetotide (PSMA-11)](https://nuclide.cc/drugs/ga68-psma-11/)
- technologies: [Cold kit formulation](https://nuclide.cc/technologies/cold-kit-formulation/), [Cyclotron isotope production (F-18, Ga-68, Cu-64, Zr-89, At-211)](https://nuclide.cc/technologies/cyclotron-isotope-production/), [Germanium-68/gallium-68 generators](https://nuclide.cc/technologies/ge68-ga68-generators/), [PSMA PET](https://nuclide.cc/technologies/psma-pet/), [Radionuclide generators and cold kits](https://nuclide.cc/technologies/radionuclide-generators-kits/), [Somatostatin receptor PET (68Ga/64Cu-DOTATATE)](https://nuclide.cc/technologies/sstr-pet/)
- companies: [BWXT Medical](https://nuclide.cc/companies/bwxt-medical/), [China Isotope & Radiation Corporation](https://nuclide.cc/companies/china-isotope-radiation/), [Eckert & Ziegler](https://nuclide.cc/companies/eckert-ziegler/), [HTA (Atom Hi-Tech)](https://nuclide.cc/companies/hta-atom-hi-tech/), [IRE (Institut national des Radioéléments)](https://nuclide.cc/companies/ire/), [Isotopia Molecular Imaging](https://nuclide.cc/companies/isotopia/)

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