Show-Me State Times

A team of scientists at the University of Missouri Research Reactor (MURR) is making strides in cancer treatment with a new radioisotope, Terbium-161. Led by Heather Hennkens, an associate professor and researcher at MURR, the study focuses on producing, purifying, and formulating Terbium-161 for use in radiopharmaceuticals.

Hennkens' lab aims to optimize this radioisotope so it can be attached to a targeting molecule and used as a therapeutic "payload" to destroy tumor cells. Terbium-161 belongs to the same chemical family as Lutetium-177, which is already used in treatments for neuroendocrine tumors and prostate cancer. The similarity between these lanthanides allows for potential integration into existing treatments without developing entirely new drugs.

"This allows for the integration of terbium into existing treatments, potentially adding extra therapeutic effectiveness without requiring entirely new drug development," said Hennkens.

What distinguishes Terbium-161 is its ability to deliver additional low-energy electrons — Auger and conversion electrons — which travel short distances within tumors while causing significant damage. This feature could help treat dispersed or microscopic forms of disease, such as smaller clusters of metastasized cells.

"These low-energy electrons travel very short distances within the tumor while creating significant damage to the cancer cells along the way," Hennkens explained.

The research also emphasizes pairing these isotopes with appropriate targeting molecules to ensure they reach tumor cells while avoiding healthy tissues.

MURR is currently the only U.S. supplier of four medical isotopes, and there are hopes that Terbium-161 will join this list. As scientists refine production processes, they aim to establish domestic production capabilities that could reduce reliance on foreign sources and bolster the U.S. medical isotope supply chain.

The team's findings were published in Radiochimica Acta under the title “Production and purification of research scale 161Tb using cation-exchange semi-preparative HPLC for radiopharmaceutical applications.” Co-authors include researchers from Mizzou, Brookhaven National Laboratory, and the University of Washington.