Automated Preparation of 211At for Targeted Alpha Therapy Applications

A primary goal of the Department of Energy (DOE) Isotope Program is to support research and development of methods and technologies that assure availability of critical radioisotopes. High-purity therapeutic isotope products are essential for high-yield protein radiolabeling for radiopharmaceutical use.This project will develop a system to automate the production of alpha-emitting therapeutic radionuclides such as astatine-211.These radionuclides have been identified as candidates in the treatment of leukemia, lymphoma, and micro-metastatic disease.Existing manual methods are tedious, time consuming and pose radiological dose risks to technicians. Furthermore, automated systems provide a means of autonomous, remote operations that are essential in preparation of high levels of radioactive materials within enclosed spaces (e.g., hot cells and glove boxes). During phase I, the feasibility of three of the unit operations in the astatine-211 preparation scheme were demonstrated and these were integrated into a functioning Engineering Development Model.In the next phase of this endeavor, all the unit operations in the multi-step chemical purification protocol will be engineered for inclusion in an integrated and automated Advanced Development Model suited for testing by early adopters of the technology.Diagnostic sensors and software controls will be developed and incorporated to ensure that the final system meets the standards of current Good Laboratory Practices. Specifically, steps that include target dissolution, acid conversion, solid phase extraction, purified product neutralization, de-watering and antibody labelling in the conceived astatine-211 preparation process will be studied. Once these unit operations are developed and the complete system engineered and constructed, the resulting systems will be deployed at selected cyclotron facilities around the country that can produce astatine-211 to facilitate research and clinical studies on the efficacy of these radio pharmaceuticals.A dispersed network of facilities capable of producing these radioisotopes is essential because of the short half-life (7.2 hours) of the isotope of interest.To be useful as a therapeutic agent, chemical preparation of the isotope must occur close to where it will be used.By automating the preparation process, the routine supply of this isotope, first for research and clinical studies, and eventually for routine patient treatment, will be realized. Initial marketing of this system will be directed at domestic use, and thereafter, its usefulness to an international market will also be pursued.