By The Texas A&M System National Laboratories Office
Researchers from Texas A&M University (TAMU) and Los Alamos National Laboratory (LANL) are collaborating to produce radioactive isotopes which could improve future cancer treatments. This collaboration is made possible by the Texas A&M University System National Laboratories Office and LANL.
Sherry Yennello, Ph.D., Lauren McIntosh, Ph.D. and Evgeny Tereshatov, Ph.D. from the TAMU Cyclotron Institute (CI), Jonathan D. Burns, Ph.D. from the Texas A&M Engineering Experiment Station Nuclear Engineering and Science Center, a member of the Texas A&M University System, and Eva Birnbaum, Ph.D., Michael Fassbender, Ph.D., Stosh Kozimor, Ph.D. and Etienne Vermeulen, Ph.D. from the LANL Isotope Program are establishing capabilities at the CI to produce medically relevant alpha emitters for targeted alpha therapy.
The researchers are leveraging the almost 45-years of experience of isotope production at LANL to establish production capabilities at TAMU that do not currently exist. Birnbaum stated, “The LANL Isotope Program is pleased to share our experience in isotope production to facilitate the growth of a university partner in the network. TAMU brings unique capabilities to the table, as isotopes can be produced on the TAMU cyclotron that expand beyond what we can make with protons alone.”
Isotopes are atoms of elements from the periodic table that have various numbers of neutrons in their nuclei. In their basic form, elements have the same number of protons which match their atomic number. Atoms also have an atomic number determined by the number of protons and neutrons in the atom. Since an isotope has neutrons in addition to protons, the mass number is higher than the atomic number. Isotopes are written based on their mass number. The focus isotopes in this project are astatine-211 (At-211) and terbium-149 (Tb-149).
Radioactive isotopes emit alpha, beta, or gamma radiation and have several medical imaging and therapy applications. Alpha emitters are a particular interest in cancer treatment research because they emit a lot of energy in a short-range, which can destroy cancer cells while limiting damage to surrounding healthy tissue. This behavior differs from beta or gamma radiation because they emit the energy over a longer-range. Recently, molecules that target specific cancer cells have been developed that are useful in targeted alpha therapy, a process in which an alpha emitter that is capable of high damage at a short range can be targeted at cancer cells. Both At-211 and Tb-149 are alpha emitters. To emphasize the importance of this project, Yennello explained, “We’re enabling curing cancer from the inside out.”
There are two areas these researchers need to improve in order for the CI to be able to produce these isotopes, targetry and separation. To create At-211, a high-powered alpha particle beam is impinged on a plate of bismuth to cause a nuclear reaction that produces the isotopes. One challenge with the bismuth targets is that it has poor heat tolerance and a low melting point so, it is important to find a way to adequately cool the plate. Using a thin target is also important to making the isotope separation process more efficient, which supports the goal for separation: to find a method that produces a consistent amount of the isotope while minimizing the complexity of the process.
To summarize the importance of this collaboration, Burns explained, “The LANL-TAMUS Collaborative Research Program has provided a platform for us to engage with world experts on a very important problem, and even in the early stages of this collaboration, has stimulated progress.”