32P Radiosynoviorthesis in children with hemophilia.

BACKGROUND: This study was performed to prospectively evaluate the safety, efficacy, and cost of injecting P-colloid into joints of children with hemophilia and synovitis to decrease the rate of joint bleeding. PATIENTS AND METHODS: Eligibility included a diagnosis of hemophilia, history of more than six hemorrhages into a joint within a 6-month period, and evidence of synovitis by objective imaging. With written, informed consent, 0.25 to 1.0 mCi of P-colloid was injected into the problem joints. Safety was monitored by external beta-scanning and physical assessment. Efficacy was determined by analysis of the change in joint hemorrhage frequency from 6 months before and up to 96 months after the injection using a signed-rank test. Physical assessment and pain assessment were analyzed similarly using values obtained within 1 week before and 6 months after the radiosynoviorthesis. Cost was modeled using charges from the authors' institution in relation to existing alternative therapies.
RESULTS: One hundred injections were given into 91 joints in 59 children. Seven children had high-titer neutralizing antibodies to factor VIII or IX. Nine children were infected with HIV. Joints injected included 44 ankles, 19 knees, 27 elbows, and 1 shoulder. Nine joints required reinjection. All children showed a significant decrease in bleeding rate (P < 0.0001) and pain (P = 0.03), with improved physical function (P = 0.02). In one child acute lymphocytic leukemia developed, but it was judged unrelated to the two P injections that he had received 3 and 10 months before the leukemia diagnosis. There were no cases of bleeding, infection, or inflammation caused by the injection. Cost was substantially less than medical and surgical alternatives.
CONCLUSIONS: Radiosynoviorthesis is effective in limiting the frequency of joint hemorrhage, decreasing pain and improving function in children with hemophilia. However, long-term safety studies are needed.