Radioactive injection helps arthritics

Press, 2 April 1985, Page 39

Radioactive injection helps arthritics

NZPA-AP Boston Doctors say they can temporarily ease the pain and swelling of rheumatoid arthritis and help victims walk again by injecting a radioactive element direct into their diseased knees. The experimental treatment, called radiation synovectomy, appears to help patients whose arthritis cannot be relieved by any of the standard drugs now’ available, say Harvard Medical School researchers. The treatment has been used on 150 patients over the last four years under the direction of Dr Clement Sledge. It reduced or eliminated pain and swelling in 80 per cent of those cases, said Dr Mark Snyder. Many of the patients who had largely single-joint involvement recovered to the point where their gait was only slightly impaired, Dr Snyder said. “If you see them for the first time two or three

years afterward, sometimes it is hard to tell that they ever even had rheumatoid arthritis involving that joint.” The treatment works by destroying the painfully inflamed and swollen lining of the knee joint. Healthy lining eventually grows back, and patients begin to feel improvement after about three months. According to Dr Snyder, the researchers believe that the lining will come back in such a state that it is less likely to once again “become involved in joint inflammation and, we hope, destruction.” Rheumatoid arthritis is an inflammatory joint disease that affects about 1 per cent of adults. Fifty-six per cent eventually suffer damage to their knees. A minority of those with knee damage, probably less than a third, are not helped by anti-inflammatory drugs. The researchers say these people appear to be the best

candidates for the treatment. “It has a lot of attractive qualities if it can be worked out,” said Dr Joseph Lane, president of the Orthopaedic Research Society. “It is a very exciting principle.” Other researchers have experimented with similar techniques, but an important major drawback has been the tendency of the radiation to leak out of the knee, where it may cause cancer. The Harvard researchers avoided this problem by bonding the radioactive material to another molecule that is absorbed by the lining and stays inside the knee. Only about threetenths of one per cent of the radiation escapes. They use a very shortlived isotope called dyspro-sium-165. The radiation penetrates only about the thickness of the inflamed knee lining and it decays so quickly that it is virtually gone within a day. !■