New Isotope Production Could Aid Cancer Research and Treatment
Studies are currently underway to determine if a radioactive element, actinium 225 (Ac-225), could provide a new inroad for cancer treatment. LANL, in conjunction with two other Department of Energy laboratories, is working to create enough of the material to supply clinical trials as research continues. Should Ac-225 prove to be an effective treatment, the facilities are preparing to create an adequate and stable supply.
Interest in producing Ac-225 lies in the material’s ability to supply high doses of energy to destroy cancer cells while leaving nearby healthy tissue intact. While this has always been the goal of radiation therapy, an alpha emitter such as Ac-225 could be administered within a tumor to destroy cancer cells, and its effects would extend only three cell lengths beyond the target area. Current therapies are less precise. Plus, with a half-life of only 10 days (it loses half of its radioactive energy during that time), Ac-225 stays in the body long enough to produce its benefits, but eventually decays into bismuth (the active ingredient in Pepto-Bismol) and naturally leaves the body. Not only could the element help wipe out the cancer cells, but during its energy decay, its “daughter” isotopes could also provide cancer-fighting energy, which might make it even more effective while in place. The fact that the alpha particles emitted travel such a short distance and are easily blocked means nearby tissue is safe, as are any nearby humans, so patients don’t have to be isolated during treatment.
As with any therapy, doctors have always had to weigh the benefits of a potential solution against its side effects. Radiation treatment is a relatively new field, and its use is frequently rejected due to its potential to damage healthy parts of the body. Ac-225 has the potential to make such treatments safer and more effective.
Some Ac-225 is produced from nuclear fuel, but the amounts obtained have been very small, expensive to create, and can’t meet ongoing demands. Using proton beams, such as those available at the Lab’s Isotope Production Facility (IPF), may make it possible to help produce enough to meet the world’s current and future demands.
Because Ac-225 does have a short half-life, it can’t be stockpiled and a constant supply is needed. Since the IPF only runs when the Los Alamos Neutron Science Center is operational, which is six to seven months per year (the rest of the time it’s undergoing maintenance), an additional supplier is needed. Brookhaven National Laboratory will help keep the supply stable, but part of the research has entailed figuring out how to produce Ac-225 with proton beams of different strengths, ranging from 100 to 800 megaelectron volts. Another Department of Energy facility, Oak Ridge National Laboratory, is also playing a role in the research by assisting in the development of the process to prepare Ac-225 for medical use once it has been created.
The work taking place at the three locations is still preliminary, but the facilities are working together to develop a plan for full-scale production.
Cancer is never a good diagnosis, but this work could eventually help provide a new tool to get people back on the track to wellness.