Carrier Added (CA) and Non-Carrier Added (NCA)
Production of 177-Lu
177-Lu is a fully synthetic isotope.
there are 2 ways to produce 177-Lu:
The final product does not contain 177m-Lu and is referred to as Non-Carrier Added (NCA).
The cost of producing 177-Lu via the indirect route is substantially more expensive than via the direct route due to the cost of starting material (176-Yb) and since the manufacturing process is challenging as it requires to separate micro amounts of 177-Lu from macro amounts of 176-Yb with a 25% material loss causing a significantly lower efficiency in production.
ISOTOPIA have developed a unique separation method that reduced the material loss to 10%.
NCA 177-Lu is preferred by the environmental authorities because no long-lived isotope impurities (177m-Lu) exist in the end product.
Why 177-Lu is gaining popularity in radioligand therapy (RLT).
177-Lu is a medium-energy ß-emitter (490 keV) with Long physical half-life of 6.7 days, which is helpful for synthesis and transport, and average beta – particle range in soft tissue of 670 nm and maximal tissue penetration of 1-2 mm. Another benefit of 177-Lu is that it produces low energy gammas (113 keV, 208 keV), suitable for imaging purposes, allowing biodistribution and excretion kinetics to be monitored and calculating dosimetry with SPECT-CT. 177-Lu has favorable chemistry for chelation, therefore it is gaining popularity for therapy applications.
Haim Golan MD MSc
Chief Medical Office