Comparison of two yttrium-90 regimens in inflammatory and osteoarthropathies

Safety and Efficacy of Radiosynoviorthesis: A Prospective Canadian Multicenter Study

Radiosynoviorthesis is approved in several European countries and the United States to treat refractory synovitis in many inflammatory joint diseases, such as rheumatoid arthritis, spondyloarthropathies, and other arthritic joint diseases. No radiopharmaceuticals for radiosynoviorthesis are currently approved in Canada. The aim of this Health Canada-approved trial was to demonstrate the safety and efficacy of radiosynoviorthesis. Methods: Between July 2012 and November 2017, we conducted a multicenter, prospective, interventional Canadian trial. Patients (n = 360) with synovitis refractory to standard treatments after failing 2 intraarticular glucocorticoid injections were included. They were followed up at 3, 6, and 12 mo. Outcome measures included adverse events (AEs) and clinical signs of synovitis (pain, swelling, and joint effusion) measured with the Health Assessment Questionnaire Disability Index, the Disease Activity Score, and the Visual Analog Scale. Results: In total, 392 joints were treated, including those reinjected after 6 mo (n = 34). Of these, 83.4% (327/392) were injected with [90Y]Y-citrate for the knees and 9.9% (39/392) with [186Re]Re-sulfide for medium-sized joints. Of the joints treated, 82.7% (324/392) were knees. Fifty-five AEs, most of them of mild grade, occurred and resolved without sequelae and were not life-threatening. The incidence of radiosynoviorthesis-related AEs was 9.4% (34/360). The proportion of patients showing an improvement in synovitis symptoms after radiosynoviorthesis was significant at 3 mo and was maintained up to 12 mo (P < 0.001). Conclusion: This study confirmed the safety of radiosynoviorthesis in the treatment of patients with synovitis refractory to standard treatments. There is evidence of sustained clinical efficacy at 12 mo, suggesting that radiosynoviorthesis is an effective treatment for improving synovitis symptoms.

EULAR recommendations for intra-articular therapies

OBJECTIVES

To establish evidence-based recommendations to guide health professionals using intra-articular therapies (IAT) in adult patients with peripheral arthropathies.

METHODS

A multidisciplinary international task force established the objectives, users and scope and the need for background information, including systematic literature reviews) and two surveys addressed to healthcare providers and patients throughout Europe. The evidence was discussed in a face-to-face meeting, recommendations were formulated and subsequently voted for anonymously in a three-round Delphi process to obtain the final agreement. The level of evidence was assigned to each recommendation with the Oxford levels of evidence.

RESULTS

Recommendations focus on practical aspects to guide health professionals before, during and after IAT in adult patients with peripheral arthropathies. Five overarching principles and 11 recommendations were established, addressing issues related to patient information, procedure and setting, accuracy, routine and special aseptic care, safety issues and precautions to be addressed in special populations, efficacy and safety of repeated joint injections, use of local anaesthetics and aftercare.

CONCLUSION

We have developed the first evidence and expert opinion-based recommendations to guide health professionals using IAT. We hope that these recommendations will be included in different educational programmes, used by patient associations and put into practice via scientific societies to help improve uniformity and quality of care when performing IAT in peripheral adult joints.

Safety and therapeutic value of radiosynoviorthesis with yttrium-90: a Canadian single-centre experience

BACKGROUND

Yttrium-90 (90Y) is approved in several countries as a radiosynoviorthesis agent in the intra-articular treatment of synovitis, however, no such radiopharmaceuticals are approved in Canada. The aim of this Health Canada-approved study was to examine the safety and efficacy of 90Y synovectomy among patients with refractory synovitis.

METHODS

We performed a subset analysis of a prospective, phase III, single-arm, pan-Canadian trial. Large and medium-sized joints of adults with refractory inflammatory mono- or oligo-arthritis and minimal cartilage/bone destruction who failed treatment with two intra-articular corticosteroid injections were eligible. Patient follow-up was at 3, 6 and 12 months. Outcome measures included joint tenderness, swelling, effusion, joint function and bone scans.

RESULTS

A total of 79 joints were included (90% knees). The underlying diagnosis included SpA (35.2% of patients), RA (26.8%), JIA (8.5%) and other (29.6%). Non-biologic DMARDs were concurrently used in 59.2% of patients and biologic/targeted synthetic DMARDs in 31%. Five adverse events occurred, including one serious radiation burn requiring surgery. All events were non-life-threatening and resolved. Significant improvements in joint tenderness, swelling and effusion were achieved at 3 months (P < 0.001), which were maintained until 12 months. During follow-up, 92.3% of joints did not show radiographic progression. Per the treating physician, clinically important improvement in joint function was observed in 90% of joints.

CONCLUSION

Our results confirm the safety of 90Y radiosynoviorthesis in refractory synovitis and provide preliminary evidence supporting its clinical efficacy with sustained benefit at 12 months, suggesting that it is a safe alternative to surgical synovectomy in such cases. This is the first such study in a Canadian cohort.

Yttrium-90 radiation synovectomy in knee osteoarthritis: a prospective assessment at 6 and 12 months

OBJECTIVE

To assess the outcome of yttrium-90 radiation synovectomy at 6 and 12 months in patients with knee osteoarthritis unresponsive to systematic or local medical treatment.

METHODS

Consecutive patients with osteoarthritic knee pain resistant to conventional therapy and submitted to intraarticular yttrium-90 treatment because of synovial inflammation, as demonstrated by early-phase bone scintigraphy, were prospectively evaluated at 6 and/or 12 months. The assessment of the outcome of treatment was based on self-reporting of relief of knee pain limiting daily activities, measured as percentage reduction of the pretherapeutic joint discomfort with a Visual Analogue Scale. Resting and nocturnal pain also were considered, together with knee flexibility and ultrasonographic changes.

RESULTS

Among a total of 97 patients, a > or =50% Visual Analogue Scale pain palliation was experienced by 64 of 90 (71.1%) patients at 6 months and 50 of 69 (72.5%) at 12 months (P = 0.992). Moreover, nocturnal and resting pain alleviation, gain in knee flexibility and regression of large joint effusions and Baker's cysts were observed in considerable proportions. In the evaluation of the outcome of treatment in 62 patients with serial assessments using a composite criterion, 42 (67.7%) versus 40 (64.5%) had a satisfactory response at 6 and 12 months, respectively (P = 0.850). The probability of a favourable therapeutic result was inversely related to the severity of radiographic joint changes.

CONCLUSION

Yttrium-90 synovectomy exerts a beneficial therapeutic effect in a substantial proportion of patients with osteoarthritic knee pain and synovial inflammation, inadequately controlled by pharmacotherapy. Clinical improvement is inversely related to radiographic knee damage.

Radiosynoviorthesis (RSO): influencing factors and therapy monitoring

OBJECTIVE

To evaluate the effectiveness of radiosynoviorthesis (RSO) in relation to joint type and underlying disease by both self-assessment of patients and scintigraphic assessment to determine conditions under which RSO might be preferable to the sole intra-articular corticoid injection.

METHODS

Radiosynoviorthesis was performed on 136 patients for 424 joints [242 small, 130 medium-sized, and 52 large joints; 313 with rheumatoid arthritis (RA) and 111 with osteoarthritis (OA)]. The success of RSO was evaluated after 12 months by patients' estimation, and in 35 patients for 157 joints additionally by two-phase bone scintigraphy. The relative change in the scintigraphic uptake was compared with the patients' estimation.

RESULTS

The subjectively estimated success rates for the small, medium-sized, and large joints were 89% (215/242), 86% (112/130), and 79% (41/52), and for RA and OA 89% (280/313) and 79% (88/111), respectively. The scintigraphically determined response rates for small and medium-sized joints were 81% (86/106) and 69% (35/51), respectively. There was a mismatch between patients' assessment and scintigraphic assessments in 18% (28/157) with 6 false-negative and 22 false-positive estimations using scintigraphy as the standard of reference.

CONCLUSIONS

The success of RSO is higher in patients with RA than in patients with OA. For the finger, ankle, and wrist joints in RA, RSO is so promising that we would like to advocate its preference over the sole intraarticular corticoid injection. Perfusion bone scintigraphy can be used for therapy monitoring and earlier switching to RSO by showing that other therapies have failed.

Clinical effect of radiation synovectomy of the upper extremity joints: a randomised, double-blind, placebo-controlled study

PURPOSE

To compare the clinical efficacy of radiosynoviorthesis (RSO) with intra-articular radionuclide plus glucocorticoid (GC) injection (group A) with that of placebo plus GC injection (group B) for the treatment of persistent synovitis in joints of the upper extremity.

METHODS

At baseline and at 6 and 12 months after intra-articular injection, six clinical parameters were scored. Changes in clinical values over time were summed to provide a change composite index (CCI), ranging from 0 (no effect) to 12 (maximal effect). A CCI > or =6 was considered to indicate successful treatment. Differences in response rate and CCI between groups A and B were examined. Regression analyses were performed to explore whether baseline variables could predict therapeutic effect.

RESULTS

Sixty-eight joints in 44 patients were treated. Six months after intra-articular injection, response rates (CCI > or =6) were 69% (25/36) in group A and 29% (9/31) in group B (p=0.001). The mean CCIs +/- standard deviation at 6 months were 6.7+/-3.2 for group A and 3.3+/-3.8 for group B (p=0.001). At 12 months the response rates were 69% (25/36) in group A and 32% (8/25) in group B (p=0.004). The mean CCIs at 12 months were 6.8+/-3.3 for group A and 4.2+/-4.7 for group B (p= 0.046). None of the baseline variables predicted the therapeutic effect.

CONCLUSION

RSO (radionuclide plus GC) of upper extremity joints with immobilisation for 72 h shows a significantly better response rate than placebo plus GC in patients with persistent synovitis after at least one failed outpatient intra-articular GC injection.

Pretreatment macrophage infiltration of the synovium predicts the clinical effect of both radiation synovectomy and intra-articular glucocorticoids

OBJECTIVE

To explore whether pretreatment features of synovial tissue in patients with gonarthritis could predict the clinical effect of radiation synovectomy with yttrium-90 (90Y) and glucocorticoids or with intra-articular glucocorticoids alone.

METHODS

A synovial biopsy was carried out blindly 2 weeks before treatment in 66 patients with persistent gonarthritis, who were randomised to treatment either with 90Y and triamcinolone or with placebo and triamcinolone. Immunohistochemistry was used to detect T cells, macrophages, B cells, plasma cells, fibroblast-like synoviocytes, adhesion molecules and pro-inflammatory cytokines. Stained sections were evaluated by digital image analysis. Individual patient improvement was expressed using a composite change index (CCI; range 0-12). Successful treatment was defined as CCI > or = 6 after 6 months.

RESULTS

Patients with rheumatoid arthritis, psoriatic arthritis, undifferentiated arthritis and other causes of gonarthritis were included. The overall response rate was 47%. Clinical efficacy in both therapeutic groups was similar and not dependent on diagnosis. No significant differences were noted between baseline microscopic features of synovial tissue inflammation in patients with rheumatoid arthritis and in those with non-rheumatoid arthritis (ie, all diagnoses other than rheumatoid arthritis). The number of macrophages in the synovial sublining was significantly higher in responders than in non-responders (p = 0.002), independent of treatment group and diagnosis. The clinical effect was positively correlated with pretreatment total macrophage numbers (r = 0.28; p = 0.03), sublining macrophage numbers (r = 0.34; p = 0.005) and vascular cell adhesion molecule 1 expression (r = 0.25; p = 0.04).

CONCLUSION

The observations support the view that intra-articular treatment either with 90Y and glucocorticoids or with glucocorticoids alone is especially successful in patients with marked synovial inflammation.

Is radiation synovectomy for arthritis of the knee more effective than intraarticular treatment with glucocorticoids? Results of an eighteen-month, randomized, double-blind, placebo-controlled, crossover trial

OBJECTIVE

To compare the clinical efficacy and safety of radiation synovectomy (RSO) with intraarticular (IA) yttrium-90 plus glucocorticoids (GCs) with the efficacy and safety of IA placebo yttrium plus GCs and to identify parameters that predict efficacy.

METHODS

The knees of 97 patients with persistent arthritis despite outpatient treatment with IA GCs (n = 113 knees), were treated with either IA (90)Y plus GCs (50%) or IA placebo yttrium plus GCs (50%), followed by 3 days of bed rest in the hospital clinic, with splinting of the treated knee. Predominant diagnoses were undifferentiated arthritis (39%) and rheumatoid arthritis (32%). The clinical effect of therapy was assessed at 6 months using a composite change index (CCI; range 0-12). The primary outcome measure was the response rate (i.e., the percentage of joints with a CCI > or =6). Knees with persistent arthritis after 6 months underwent crossover therapy (51% of the (90)Y plus GCs group versus 45% of the placebo plus GCs group). Adverse effects and radiologic damage during followup were documented.

RESULTS

Neither the response rate (48% in both groups), the mean CCI, nor the duration of remission was significantly different between groups. No clinically relevant short-term adverse effects were observed, except for progression of radiologic damage in 34% of the (90)Y plus GCs group versus 28% of the placebo plus GCs group (knee prosthesis placement in 8% versus 1%). The functional and radiologic status at study entry predicted the clinical effect.

CONCLUSION

Treatment with (90)Y plus GCs with bed rest and splinting is not superior to IA GCs with bed rest and splinting. Over the short term, both treatments appeared to be safe, although a negative effect of (90)Y on cartilage and bone cannot be ruled out. Thus, it appears that RSO with (90)Y should no longer be considered the treatment of first choice for persistent arthritis of the knee.

Radiosynoviorthesis in Osteoarthritis and Other Disorders with Concomitant Synovitis in Comparison to Rheumatoid Arthritis

AIM

The aim of this study was to evaluate the effectiveness of radiosynoviorthesis (RSO) in osteoarthritis and other disorders with concomitant synovitis versus rheumatoid arthritis by means of a standardized questionnaire.

METHODS

Eight-hundred and three RSO treatments were monitored in 691 patients by seven centers in three countries, using standardized questionnaires. Patients were assigned to three groups according to their age (20-40, 41-60, and 61-80 years). Additionally, the data was analyzed separately for patients with rheumatoid arthritis (group A) and those with osteoarthritis, psoriasis arthritis, pigmental villonodular synovitis, or persistent effusions after joint replacement (group B).

RESULTS

Quality of life improved in 78% of group A and 59% of group B (p < 0.01). Ameliorations of joint pain, swelling/effusion, or flexibility were found in 80% of group A and 56% of group B (p < 0.01). The response rate was similar for small- and large-sized joints in group A, but was significantly higher for large-sized joints in group B (p < 0.01). The positive effects on joint pain, swelling/effusion, or flexibility lasted longer in group A (p < 0.01). Repeated RSOs were as effective as initial RSOs. The clinical outcome was not influenced by age, gender, or transient immobilization for 48 hours after RSO.

CONCLUSION

Although slightly more efficient in rheumatoid arthritis, RSO represents an effective treatment option also in osteoarthritis and other disorders with concomitant synovitis.

Clinical efficacy of radiation synovectomy in digital joint osteoarthritis

PURPOSE

Radiation synovectomy was developed for local treatment of rheumatoid arthritis. In this study, the long-term efficacy of radiation synovectomy was retrospectively evaluated in patients with osteoarthritis (activated arthrosis) of the digital joints using an algofunctional score.

METHODS

Fifty-three digital joints in 29 patients (mean age 64.8 years) were treated by intra-articular injection of 169Er citrate. All joints were painful despite pharmacotherapy and showed an elevated blood pool pattern in a pretherapeutic three-phase bone scan, indicative for local synovitis. The patients were asked to classify their complaints with respect to different daily manual activities on a ten-step pain scale from 1 (total disability) to 10 (lack of any impairment) prior to and after treatment, with a mean follow-up of 41 months. Local signs of osteoarthritis such as joint swelling or pain were additionally evaluated and were scored from progression of complaints to excellent improvement based on patient self-evaluation.

RESULTS

All patients reported a pronounced improvement in their manual activities. The mean total score of 4.73+/-0.58 for all activities prior to treatment increased significantly to 6.79+/-0.47 after radiation synovectomy (p<0.05). The best results were obtained in the thumb base joints, whereas distal interphalangeal joints were frequently resistant to therapy.

CONCLUSION

Radiation synovectomy is highly effective in digital joint osteoarthritis with concomitant local synovitis.

Intra-articular therapy in osteoarthritis

The medical literature was reviewed from 1968-2002 using Medline and the key words "intra-articular" and "osteoarthritis" to determine the various intra-articular therapies used in the treatment of osteoarthritis. Corticosteroids and hyaluronic acid are the most frequently used intra-articular therapies in osteoarthritis. Other intra-articular substances such as orgotein, radiation synovectomy, dextrose prolotherapy, silicone, saline lavage, saline injection without lavage, analgesic agents, non-steroidal anti-inflammatory drugs, glucosamine, somatostatin, sodium pentosan polysulfate, chloroquine, mucopolysaccharide polysulfuric acid ester, lactic acid solution, and thiotepa cytostatica have been investigated as potentially therapeutic in the treatment of arthritic joints. Despite the lack of strong, convincing, and reproducible evidence that any of the intra-articular therapies significantly alters the progression of osteoarthritis, corticosteroids and hyaluronic acid are widely used in patients who have failed other therapeutic modalities for lack of efficacy or toxicity. As a practical approach for a knee with effusion, steroid injections should be considered while the presence of symptomatic "dry" knees may favour the hyaluronic acid approach. The virtual absence of serious side effects, coupled with the perceived benefits, make these approaches attractive.

Radiation synovectomy with holmium-166 ferric hydroxide macroaggregate in equine metacarpophalangeal and metatarsophalangeal joints

OBJECTIVES

To evaluate the effects of radiation synovectomy (RSYN) with holmium-166 ferric hydroxide macroaggregate (Ho-166 FHMA) on synovium and synovial fluid in normal metacarpo- and metatarsophalangeal joints of horses and to determine intraarticular distribution of radioactivity after Ho-166 FHMA treatment.

STUDY DESIGN

Either Ho-166 FHMA or nonradioactive Ho-165 FHMA was injected into metacarpo- or metatarsophalangeal joints.

ANIMALS

Six adult mixed-breed horses without any clinical evidence of metacarpo- or metatarsophalangeal joint disease.

METHODS

Joints were injected with a single high dose of Ho-166 FHMA (mean, 1,000 MBq/joint) or a nonradioactive Ho-165 FHMA preparation (controls). Clinical examination, arthroscopy, synovial fluid analyses, and histologic studies were performed to detect effects of RSYN. Scintigraphy was used to localize intraarticular distribution of Ho-166 FHMA.

RESULTS

Ho-166 FHMA treatment induced joint inflammation leading to regional edema, effusion, and scar tissue formation. Scintigraphy revealed the highest intensity of radioactivity in the proximal plantar joint pouch, at which the Ho-166 FHMA treatment caused multifocal necrosis. In the dorsal joint pouch, however, arthroscopic study and histologic analysis showed very little effect of RSYN. There was no regeneration of synovium evident within 2 months. Synovial fluid protein concentration was significantly (P <.01) elevated, and some residual radioactivity remained for 5 days after Ho-166 FHMA injection.

CONCLUSIONS

Injection of a single high dose of Ho-166 FHMA caused multifocal necrosis of synovium and deep, soft-tissue injury in equine fetlock joints.

CLINICAL RELEVANCE

Inflamed equine joints with synovial lining hyperplasia could benefit from Ho-166 FHMA-induced radiation synovectomy if excessive scar tissue formation can be avoided.

Comparison of Tc-99m HIG and three-phase Tc-99m MDP bone scintigraphy for evaluating the efficacy of Yttrium-90 silicate radionuclide synovectomy

PURPOSE

The aim of this study was to compare Tc-99m human immunoglobulin (HIG) and three-phase Tc-99m MDP bone scintigraphy for the assessment of the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis.

MATERIALS AND METHODS

Fifteen patients with rheumatoid arthritis and chronic persistent synovitis in 23 knee joints had radionuclide synovectomy with Y-90 silicate. The patients underwent imaging before and 3, 6, 9, and 12 months after therapy using clinical evaluation, Tc-99m HIG scintigraphy, and three-phase Tc-99m MDP bone scintigraphy.

RESULTS

In the 13 of 23 knee joints that showed successful clinical results with Y-90 therapy, the Tc-99m HIG index values obtained 3 months after radionuclide synovectomy were significantly lower than the pretreatment index values (P < 0.001). In the same 13 joints, the Tc-99m MDP index values (in the blood-pool and delayed phases) before and 3 months after therapy were statistically similar. Six months after injection, these values were significantly lower in both the blood-pool (P < 0.001) and late (P < 0.05) phases in all 13 joints. In the other 10 of 23 knee joints that did not respond to treatment, the Tc-99m MDP and Tc-99m HIG index values were statistically similar before and after Y-90 therapy.

CONCLUSIONS

Based on these findings, Tc-99m HIG scintigraphy appears to be a valuable method that complements clinical assessment of the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis, starting in the early post-treatment period. However, three-phase Tc-99m MDP bone scintigraphy may be valuable in the late postsynovectomy period.

Clinical outcome of radiosynoviorthesis: a meta-analysis including 2190 treated joints

A variety of indications for radiosynoviorthesis have been reported in literature, but the clinical outcome differs and depends on the primary disease and the pre-existing degenerative changes. This metaanalysis was carried out to establish groups for radiosynoviorthesis based on clinical outcome with respect to primary disease, clinical stage and the pre-existing degenerative changes. The literature search was carried out using the MEDLINE search term 'radionuclide synovectomy'. Based on reports in the literature we determined groups for radiosynoviorthesis for clinical use. Our literature list comprised 2190 joints that were treated with radiosynoviorthesis. The overall response rate for all treated joints was 72.5+/-17%. The mean improvement rate for the treated joints in rheumatoid arthritis was 66.7+/-15.4%. For osteoarthritis the success rate was 56+/-11%, with better results in case of minimal radiological changes. Radiosynoviorthesis in patients with changes according to Steinbrocker I and II was successful in 72.8+/-12.3%, and in 64+/-17.3%, respectively. Steinbrocker III and IV had a mean success rate of 52.4+/-23.6%. In the case of haemophilia and Willebrand's disease a reduction of joint bleedings and factor usages after radiosynoviorthesis was evident in 91+/-4.3%. In patients with pigmented villonodular synovitis radiosynoviorthesis was successful in 77.3+/-25.3%. It is concluded that radiosynoviorthesis provides better results in rheumatoid arthritis than in osteoarthritis. Minimal or moderate changes according to Steinbrocker stages I and II respond better to radionuclide therapy than do stages III and IV. Deformed or unstable joints might fail treatment and therefore surgical interventions should be considered. Close cooperation with orthopaedists and rheumatologists is necessary to consider radiosynoviorthesis in each patient to ensure optimal medical care.

Utility of Tc-99m human polyclonal immunoglobulin G scintigraphy for assessing the efficacy of yttrium-90 silicate therapy in rheumatoid knee synovitis

PURPOSE

The aim of this study was to determine the utility of Tc-99m human polyclonal immunoglobulin G (HIG) scintigraphy for evaluating the efficacy of yttrium-90 (Y-90) silicate therapy in rheumatoid knee synovitis.

MATERIALS AND METHODS

Fifteen patients (13 women, 2 men; mean age, 53.5 +/- 8.4 years) with rheumatoid arthritis had radionuclide synovectomy using 185 MBq (5 mCi) Y-90 silicate to evaluate 24 knee joints with chronic persistent synovitis. Radiologic and clinical evaluations and Tc-99m HIG scans were performed in each patient before radionuclide synovectomy. Each patient was reassessed 3, 6, 9, and 12 months after therapy using clinical examination and Tc-99m HIG scintigraphy.

RESULTS

In 14 of 24 knee joints (4 Larsen stage I, 10 Larsen stage II) that had excellent or good clinical responses to Y-90 silicate therapy, the Tc-99m HIG index values 3 months after treatment were significantly lower than the pretreatment index values (P < 0.001). In 13 of these 14 joints, these low index values and clinical results remained constant throughout the 1 year of follow-up. One patient (1 of the 14 knee joints) experienced severe pain and swelling as a result of recurrent arthritis at 9 months, and the Tc-99m HIG index value increased at 9 months and remained high 12 months after therapy. In 10 of 24 knee joints (4 Larsen stage II, 6 Larsen stage III) that had a fair or poor clinical response, Tc-99m HIG index values were statistically similar before and after radionuclide therapy.

CONCLUSIONS

Quantitative Tc-99m HIG scintigraphy is a valuable method for assessing the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis.

Long-term results of radiation synovectomy: a clinical follow-up study

Radiation synovectomy by intra-articular injection of beta-emitting radionuclides is a reliable and easy-to-perform therapy without harmful side effects for the treatment of inflammatory rheumatoid as well as degenerative joint diseases. The indication for radiation synovectomy is based on both clinical symptoms and on proven hyperperfusion, with active synovitis being seen on a pre-therapeutic three-phase bone scan. In this study, the clinical response after 6-18 months, evaluated by a standardized questionnaire, was compared with the reduction of synovitis seen on three-phase bone scintigraphy after treatment of 475 joints in 151 patients. The best clinical results were obtained in cases of true rheumatoid arthritis (73.4%), with less in other kinds of arthritis (48.8%) such as psoriatic or reactive arthritis. Because of the inflamed synovium being the main target tissue, clinical results in osteoarthritis with severe bone destruction are poorer (33.9%). However, synovitis can be markedly reduced (in approximately 70%), regardless of the underlying diagnosis, as shown by post-therapeutic three-phase bone scanning. Radiation synovectomy can be recommended in all kinds of arthritis. It should also be considered in cases of osteoarthritis as a last therapeutic option prior to joint replacement.

The knee joint in rheumatoid arthritis

Rheumatoid arthritis may present in the knee within a wide spectrum of manifestations. Disease progression, treatment protocols, surgical treatments and the possible complications of these treatments differ distinctly from those of osteoarthritis.

Radiochemical synovectomy

Radiochemical synovectomies have been used for nearly fifty years for the treatment of persistent monoarticular synovitis refractory to antiinflammatory drugs, disease modifying drugs, and intraarticular corticosteroids. It is a therapeutic alternative to surgical synovectomy. There are controversies concerning safety, choice of appropriate agent, and logistics of administration. These concerns are discussed in addition to reviewing some of the more recent trials examining the efficacy of radiochemical synovectomy. It is clear that in properly selected patients this procedure is safe and beneficial.

Innovative treatment approaches for rheumatoid arthritis. Non-surgical synovectomy

Rheumatoid patients with intractable knee effusions may benefit from medical or radio-isotopic synoviorthesis. These offer more convenient, less costly alternatives to surgery with similar long-term outcome. Temporary symptomatic relief may be obtained, but disease progression is unaffected. Potential adverse effects include development of osteoarthrosis with osmic acid and teratogenicity and mutagenicity with alkylating agents and radioisotopes.

Beta-particle dosimetry in radiation synovectomy

Beta-particle dosimetry of various radionuclides used in the treatment of rheumatoid arthritis was estimated using Monte Carlo radiation transport simulation coupled with experiments using reactor-produced radionuclides and radiachromic film dosimeters inserted into joint phantoms and the knees of cadavers. Results are presented as absorbed dose factors (cGy-cm2/MBq-s) versus depth in a mathematical model of the rheumatoid joint which includes regions of bone, articular cartilage, joint capsule, and tissue (synovium) found in all synovial joints. The factors can be used to estimate absorbed dose and dose rate distributions in treated joints. In particular, guidance is provided for those interested in (a) a given radionuclide's therapeutic range, (b) the amount of radioactivity to administer on a case-by-case basis, (c) the expected therapeutic dose to synovium, and (d) the radiation dose imparted to other, nontarget components in the joint, including bone and articular cartilage.

Treatment of psoriatic arthritis

The treatment of psoriatic arthritis has acquired relevance in the past few years because of advances and better understanding of the pathogenetic mechanisms implicated in the disease, and also because of recognition that this disorder is not a benign disease as was previously thought. The general principles of management for any inflammatory arthritis, including pharmacological, surgical and rehabilitative treatment, are to be used, with concomitant therapeutic management of skin involvement. Non-steroidal anti-inflammatory drugs constitute the mainstay of pharmacological therapy for most patients, with a good clinical response observed in 75-85%. Early use of remittive agents, especially methotrexate, is indicated in patients with a poor response to NSAIDs or those with polyarticular and progressive joint involvement. Patients who are refractory to conventional therapy should be considered for newer and potentially more toxic therapeutic modalities such as cyclosporin A and retinoids.

Yttrium synovectomy: a meta-analysis of the literature

BACKGROUND

Yttrium synovectomy for chronic synovitis of the knee enjoys widespread usage in Australia with approximately 400 patients receiving yttrium-90 in 1991. Despite abundant anecdotal evidence of its efficacy there is a paucity of controlled trials and those that have been done have produced conflicting results and have been of insufficient sample size.

AIMS

To critically and quantitatively evaluate the published English literature on comparative trials of yttrium-90 therapy for chronic synovitis of the knee.

METHODS

The technique of meta-analysis was utilised. The literature search was carried out using the MeSH terms of synovectomy and knee; and yttrium. This was augmented by referring to reviews, current textbooks and back-references. Outcome measures varied between trials but could be grouped as treatment success. The Peto modification of Mantel and Haenszl was used for statistical pooling of data yielding a pooled odds ratio (OR).

RESULTS

The literature search revealed ten controlled trials of which two were excluded from further analysis. Yttrium was superior to placebo (OR 2.42, 95% CI 1.02-5.73) but this result should be interpreted with caution due to possible publication bias. Yttrium was not superior to triamcinolone (OR 1.89, 95% CI 0.81-10.55) or other active modalities (OR 1.04, 95% CI 0.72-1.52). Further research comparing yttrium with other modalities is necessary to properly determine its place in rheumatological practice.