Ge68s

Ge-68, or germanium-68, is a radioactive isotope of germanium with mass number 68. It is produced artificially and is used primarily as the parent nuclide in Ge-68/Ga-68 generators, which supply Ga-68 for positron emission tomography (PET) radiopharmaceuticals. Ge-68 decays by electron capture to Ga-68 with a half-life of about 270.8 days. Ga-68 then decays by positron emission to Zn-68 with a half-life of about 68 minutes, enabling PET imaging.

Production of Ge-68 is typically achieved in cyclotrons by irradiating enriched Ga-69 targets with protons, via the Ga-69(p,2n)Ge-68 reaction. Alternative production routes include high-energy spallation processes. The long half-life of Ge-68 makes it suitable for use in generators that can be shipped and stored for extended periods, while allowing on-site generation of Ga-68 as needed.

Applications and use in medicine are the primary drivers of Ge-68 production. The Ge-68/Ga-68 generator provides a continuous source of Ga-68 for labeling radiopharmaceuticals such as Ga-68-DOTATATE, Ga-68-DOTATOC, and Ga-68-PSMA-11, among others. These tracers are employed in PET imaging for neuroendocrine tumors, prostate cancer, and other conditions, benefiting from Ga-68’s favorable decay characteristics and imaging properties.

Safety and regulation are important considerations, as Ge-68 is radioactive and long-lived. Handling requires appropriate shielding, monitoring, and waste management in compliance with radiopharmaceutical standards and national regulatory frameworks. Ge-68 is not found naturally in meaningful quantities and is produced for medical use in specialized facilities.