Attacking cancer with isotopes

"The beauty of something like an alpha emitter such as actinium-225 is that it's powerful enough to be able to treat the metastatic disease as well as the primary tumor," said Sandra Davern, head of ORNL's Radioisotope Research and Development Section.

The short range of the isotope's effects means the impact on normal tissues beyond the tumor is minimal. "That's a huge leap forward in how to treat disease, because it's a precision therapy," Davern said.

Alpha particles consist of two protons and two neutrons. They are especially promising in the fight against cancer for two reasons: the intense energy they emit and the short distance that energy travels.

In the body, an alpha particle blasts everything within two to 10 cells. Beta particles, consisting of high-energy electrons or positrons, are also used in nuclear medicine, but they radiate 10 times farther while delivering less energy.