Radiology: Rings and Cancer

In treating certain types of cancer by radiation, doctors implant little gold “seeds” inside the growths. The seeds are actually hollow gold beads, each containing radon gas. After two or three weeks, the radon’s radioactivity is virtually gone. The harmless seeds are left in place, but a few of them may be sloughed off by the body. At Manhattan’s Memorial Sloan-Kettering Cancer Center, a nurse saved the seeds sloughed off by the tumor and had the salvaged gold made into a ring for her boy friend. He developed red patches on his finger. Memorial’s physicists found that the ring was radioactive and locked it up in a lead box where, 16 years later, it remains.

Other used seeds have been melted down and the salvaged gold has found its way into rings. In the Journal of the A.M.A., two doctors in northern New York report cancer-type changes caused by a radioactive ring. When a man had a cameo ring remodeled in 1946, the jeweler inserted a piece of “new” gold. After ten years, the man had so much discomfort on his left ring finger that he transferred the ring to his right hand. Eight years later, that finger also was irritated and inflamed, so he stopped wearing the ring. Too late. This year, the left ring finger had to be amputated for cancer.

Nuclear Alchemy. A New Jersey engineering professor and his wife, after similar experiences, have had damaged skin removed and replaced with grafts. How had the rings become contaminated? Since radon has a half life of only 3.8 days (meaning that it loses half its radioactivity in that interval), the seeds should soon have become harmless. Trouble is, the radon turns, by nuclear alchemy, into lead-210, the radioactive isotope of that normally dull metal. The lead-210 adheres to the gold. Even so, the intact seeds are safe because the lead’s rays, unlike the radon’s, remain trapped inside. But in melting for salvage, the lead is released. It takes 22 years to lose half of its activity and its potential for damage.

The Atomic Energy Commission has no control over medical radium. The states license a dozen makers of radon seeds, and keep a watch on their waste disposal. But the AEC’s Dr. John Harley is concerned lest some contaminated gold may have found its way into dentures as well as jewelry.