Brookhaven National Laboratory (BNL) has announced the shipment of the first actinium-225 (Ac-255) to be produced in a newly refurbished hot cell laboratory at the US Department of Energy's (DOE) lab. The new facilities will streamline production and shipment of the rare radioisotope for the development of new cancer treatments.

The new hot cells in use at BNL's MIRP (Image: BNL)

Ac-225 is an extremely rare alpha-emitting radioisotope that can be used in targeted alpha therapy. Scientists from BNL's Medical Isotope Research and Production (MIRP) programme have been working since 2014 as part of a DOE effort across three national laboratories to produce Ac-225, as well as Ac-225/Bi-213 generators to produce the bismuth-213 isotope, for use in clinical trials. This involves irradiating thorium-232 targets using proton accelerators at the Brookhaven and Los Alamos national laboratories, then shipping irradiated targets to Oak Ridge National Laboratory (ORNL) to extract and purify the isotope.

The effort has established reliable, routine Ac-225 production, and demonstrated that the process is scalable. But the availability of space in the specialised "hot cell" laboratory needed for processing radioactive materials has limited the amount of Ac-225 that could be made.

A metallurgical laboratory at Brookhaven, unused since the 1990s, has now been refurbished to enhance isotope processing capabilities at BNL, through a USD8.5 million investment from the DOE Science Laboratories Infrastructure programme. This has involved retrofitting the obsolete hot cell facility and labs to create a new All-Purpose (AP) Hot Cell facility.

The hot cells at the new facility were completed in March and have doubled the number of Ac-225 processing sites for DOE's Isotope Program, BNL said, and the expanded processing capacity provides redundancy so Brookhaven and ORNL can serve as backups for each other. Having both target irradiation and hot cells for processing at one laboratory also provides a more efficient way of producing larger batches of Ac-225 by removing some of the logistical challenges.

"This upgrade will streamline the overall production and distribution of Ac-225 to research centres by eliminating the need to ship material off site for final processing," said MIRP Director Cathy Cutler said. "Now we can irradiate the targets and process them right here at Brookhaven so that Ac-225 can be shipped directly to research centres."

BNL announced on 19 April that the first shipment of Ac-225 from the new facility took place in mid-March.