Vascular-targeted alpha particle emitter destroys tumor colonies in lung

  Vascular-targeted alpha particle emitter ,213Bi, destroys tumor colonies in lung. Conventional radioimmunotherapy wherein radioisotopes are delivered to tumor cells using tumor selective antibodies has not been completely successful in treatment of solid tumors. Scientists in the ORNL Life Sciences Division are developing targeting agents to direct radioisotopes to blood vessels which service tumors. The major premise is that radioisotopes parked in the tumor vessels will destroy blood vessels and tumor cells within the radiation range. A model system which targets 213Bi to mouse lungs bearing tumor colonies (micrometasteses) shows that vascular targeting works. Mice treated with this specific 213Bi-MAb are cured of preimplanted lung colonies and survive significantly longer (5-10 times) than control animals which die of lung cancer. This work shows that (1) alpha emitters are potent and useful radioisotopes for RAIT of micrometasteses, (2) vascular targeting is an efficient method of RAIT, (3) vascular targeting agents which are organ specific or tumor selective may be adequate for RAIT, (4) efforts to identify agents that target human tumor vasculature may lead to cures of cancer metasteses and should be aggressively pursued.

Contact: S. J. Kennel
Phone: 574-0825
E-mail: sj9@ornl.gov