Radiation therapy for arthritic joints.

Radiation therapy for arthritic joints

Gold compounds and the antibiotic penicillamine are traditional treatments for rheumatoid arthritis, the joint-destroying disease in which white blood cells and their immune system products invade human joints and cause inflammation. Stanford University researchers now report that high-dose irradiation of lymphoid tissues, such as the spleen and lymph nodes, may be an effective treatment in patients for whom traditional treatments have failed.

White blood cells normally circulate in the bloodstream and in lymph, the transparent fluid collected from body tissues that eventually empties into the bloodstream. The cells leave the blood and lymph and enter body tissues only when viruses or other foreign substances invade the body. But in rheumatoid arthritis, the cells accumulate in the delicate synovial membrane that surrounds joints. The membrane normally allows bones that meet at a joint to move smoothly over each other, but in arthritis, it is inflamed and causes pain when the joint is moved.

Scientists do not yet know why immune cells accumulate in arthritis-diseased joints (SN: 9/4/82, p. 156). They speculate that a virus or a genetic defect in the immune system might be the trigger, causing cells to congregate in joints.

In the present study, reported in the April ANNALS OF INTERNAL MEDICINE, 24 arthritis patients for whom gold compounds and penicillamine treatments had failed were given--over six weeks-- either high-dose (2,000 rad) or low-dose (200 rad) total lymphoid irradiation. Neither patients nor observers knew which patient received which treatment. Morning stiffness, joint tenderness, joint swelling and a composite of these factors were measured in each patient.

Patients in the high-dose group showed significant improvement compared with the low-does group in all four variables at both three and six months after the treatment ended. Patients in the low-dose group showed little improvement, but Samuel Strober, an author of the study, cautious that the small number of patients in this group (11) may have been the reason the researchers did not see significant improvement.

Patients who received high-dose irradiation had side effects ranging from fatigue and hair loss to severely low white blood cell count, according to the report. But the side effects are limited, Strober says, to the six-week treatment period and shortly thereafter. Patients are then maintained on aspirin. Traditional therapies, he says, must be given for the rest of the patient's life, creating longer-term side effects.