Radiosynovectomy in haemophilic synovitis of elbows and ankles: Is the effectiveness of yttrium-90 and rhenium-186 different?

Synovitis in hemophilia: preventing, detecting, and treating joint bleeds

INTRODUCTION

Most bleeding events in individuals with hemophilia occur within the ankle, knee, and elbow joints. Should the bleeding persist, the synovial membrane starts to hypertrophy and a vicious cycle of chronic hemophilic synovitis (CHS) occurs, leading to joint destruction.

AREAS COVERED

This article covers the prompt diagnosis of CHS by point-of-care ultrasonography (POC-US) and its treatment by means of several types of synovectomy.

EXPERT OPINION

It is essential to prevent, detect and treat hemophilic synovitis, because it indicates that the joint has bled and is at risk of bleeding further. Prophylaxis with standard half life (SHL) factor VIII (FVIII) concentrate is the standard of care for individuals with severe hemophilia A and can also be considered for selected patients with moderate disease. Several years of real-world experience with extended half life (EHL) FVIII, emicizumab, and other drugs in development will be needed to ascertain their final effect on bleeding and its complications. We must look for synovitis in individuals declaring joint pain and in asymptomatic patients, and POC-US is the most reasonable imaging instrument with which to carry out periodic joint screening. Radiosynovectomy, chemical synovectomy, and arthroscopic synovectomy markedly reduce bleeding events.

Radiosynovectomy for the Treatment of Chronic Hemophilic Synovitis: An Old Technique, but Still Very Effective

A radiosynovectomy (RS) should be indicated when recurrent articular bleeds related to chronic hemophilia synovitis (CHS) exist, established by clinical examination, and confirmed by imaging techniques that cannot be constrained with hematological prophylaxis. RS can be performed at any point in life, mainly in adolescents (>13−14 years) and adults. Intraarticular injection (IAI) of a radioactive material in children might be arduous since we need child collaboration which might include general anesthesia. RS is our initial option for management of CHS. For the knee joint we prescribe Yttrium-90, while for the elbow and ankle we prescribe Rhenium-186 (1 to 3 IAIs every 6 months). The procedure is greatly cost efficient when compared to surgical synovectomy. Chemical synovectomy with rifampicin has been reported to be efficacious, inexpensive, simple, and especially practical in developing countries where radioactive materials are not easily available. Rifampicin seems to be more efficacious when it is utilized in small joints (elbows and ankles), than when utilized in bigger ones (knees). When RS and/or chemical synovectomy fail, arthroscopic synovectomy (or open synovectomy in some cases) should be indicated. For us, surgery must be performed after the failure of 3 RSs with 6-month interims. RS is an effective and minimally invasive intervention for treatment of repeated articular bleeds due to CHS. Although it has been published that the risk of cancer does not increase, and that the amount of radioactive material used in RS is insignificant, the issue of chromosomal and/or deoxyribonucleic acid (DNA) changes remains a concern and continued surveillance is critical. As child and adulthood prophylaxis becomes more global, RS might become obsolete in the long-term.

Radiosynoviorthesis: almost seventy years of experience but still somewhat fameless

Radiosynoviorthesis (RSO) or radiation synovectomy has been practiced for more than half a century, but in many parts of the world, it is still relatively unknown and not used to its full potential in the standard care for chronic, persistent or recurrent synovitis. The working mechanism of RSO is simple yet elegant. Radiopharmaceutical particles are, after injection in the affected synovial joint, gobbled up by phagocytizing subsynovial inflammatory cells. As a consequence, the synovium will be irradiated locally resulting in synovial cell necrosis and inhibition of cell proliferation, which eventually leads to a decrease in the inflammatory response in the joint cavity. In this review RSO is once again brought to the attention and common indications for RSO are discussed. Also, appropriate activities of the administrated radiopharmaceuticals and coadministrated glucocorticoids are provided. Furthermore, a detailed database-assisted chronological overview of published literature of RSO in inflammatory and non-inflammatory diseases, like rheumatoid arthritis, psoriatic arthritis, osteoarthritis and osteochrondomatosis, hemophilic hemarthrosis and pigmented villonodular synovitis (PVNS) is provided. Based upon the published literature an indication of level of evidence of RSO is discussed. There is evidence that RSO is effective in persistent synovitis in patients with a variety of causes for synovitis, although the effectiveness seems to decrease over time. In these patients, RSO may not be used to its full potential in many parts of the world. Results in of RSO in hemophilia patients with hemarthrosis are favourable, however the evidence for the effectiveness of RSO in these patients is less firm and mainly based on case series. The evidence for the efficacy of RSO as adjuvant therapy in PVNS is, at best, of very low quality.

Effect of radiosynoviorthesis on the progression of arthropathy and haemarthrosis reduction in haemophilic patients

INTRODUCTION

Repeated haemarthrosis is widely accepted as the triggering cause of synovitis and haemophilic arthropathy. A first-line treatment of chronic synovitis is radiosynoviorthesis (RS). The aim of this study was to evaluate the RS effects on the progression of arthropathy and on a reduction in bleeding in patients with haemophilia.

METHODS

An observational-retrospective study was performed. Bleeding episodes in the 12 months following and in the 12 months preceding RS was compared. The arthropathy was clinically and radiologically analysed by age range, joint and subject, comparing those undergoing RS (Radiosynoviorthesis Group, RSG) against those not undergoing this treatment (Non-Radiosynoviorthesis Group, Non-RSG).

RESULTS

One hundred and seventy-four RS were performed in 71 patients (⁹⁰ Y in Knees and ¹⁸⁶ Re in elbows/ankles/shoulder). RS resulted in significant reduction in bleeding (582 preintervention and 168 postintervention, P < .001). In general, the level of arthropathy measured clinically and radiologically was greater with age increase in both groups (RSG and Non-RSG), especially in the 25-40 age range. A significant increase (P < .05) in the progression of arthropathy was also observed, both globally by patient and specifically for each joint, in non-RSG and RSG group.

CONCLUSION

RS is an effective method to reduce the number of haemarthrosis episodes in chronic synovitis. Moreover, RS can positively affect arthropathy by slowing down its progression. However, the results obtained suggest that arthropathy may be conditioned by the subject's age, regardless of whether or not the joint has undergone RS.

Current role for radioisotope synovectomy

Radioisotope synovectomy has been extensively used to treat patients with chronic inflammatory joint disease but has moved to a less prominent position since the introduction of new and highly effective drugs. Remaining indications are refractory synovitis, pigmented villonodular synovitis as an adjunct to surgery, and hemophilic arthropathy. The three main radioisotopes used are yttrium-90, rhenium-186, and erbium-189. Radioisotope synovectomy should be performed only by highly experienced professionals, to minimize the risk of injection-related complications. The available safety data, in particular regarding the risk of malignancy, are reassuring. The efficacy of yttrium-90 in chronic inflammatory joint disease remains controversial.