Doctors To Test Isotopes Against Cancer Hanford Scientists Produce New Hope With ‘Bismuth 213’

Hanford Nuclear Reservation scientists have produced radioactive isotopes that doctors hope will lead to a breakthrough in cancer treatment.

In November, researchers at Memorial Sloan-Kettering Cancer Center in New York City will begin the first human clinical trials of bismuth 213 produced by Hanford scientists, said Robert Schenter, group leader of the Isotope Production Office for Westinghouse Hanford Co.

They hope to use the potent isotope to kill bone marrow leukemia. The plan is to marry the alpha-emitting radioactive isotope with manmade protein to create a “biomissile” that pinpoints cancer cells and kills them.

The isotopes were chemically separated from nuclear waste from Department of Energy sites across the country.

The same technique has been used to stop almost hopeless cases of lymph cancer in clinical trials in the past few months.

In the past, medical researchers at the University of Washington and University of Texas have used isotopes - yttrium 90 and iodine 131 - that produce beta rays.

Researchers found they often could halt the spread of two kinds of lymph node cancer, and in many cases kill it.

But beta rays are relatively weak and cannot penetrate skin. So Hanford scientists looked to isotopes that emit alpha rays: particles powerful enough to blast through a brick.

“It’s like hitting your house with a wrecking ball, rather than a pellet gun,” said Darrell Fisher, a staff scientist at the Pacific Northwest Laboratory Life Sciences Center operated by Battelle-Northwest.

The engineered protein is effective because radioactivity indiscriminately injected into a patient would kill healthy cells as quickly as the malignant ones.

Researchers clone antibodies in mice that will attach themselves to specific human cancer cells. Then they marry the radioactive source to the antibiotic protein and inject the mixture into the patient.

When a radioactive protein bumps up against the correct cancer cell, it latches onto it, drawing the radiation emitter close to the cell scientists want killed.

Injected proteins that don’t find cancer cells are flushed out, limiting the exposure to radioactivity.

The nation’s push to clean up radioactive wastes may put a crimp in the medical isotope program, Schenter and others say.

For instance, there are an estimated 4,500 grams of radium - a parent to the medical isotopes - mixed with about 20 million pounds of other wastes at the Fernald, Ohio, facility.

Battelle’s Fisher wants Fernald’s radium removed before the rest of the waste is turned into glass logs.

“Fernald has the gold in the ground. … But this is a political story as well as a chemical story,” said Lane Bray, the Hanford chemist and former state representative leading the effort to chemically separate useful isotopes from parent isotopes.