Efficacy of radiosynovectomy in rheumatoid arthritis

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.

Recurrence-Free Survival after Synovectomy and Subsequent Radiosynoviorthesis in Patients with Synovitis of the Knee-A Retrospective Data Analysis

BACKGROUND

Persistent knee synovitis leads to joint discomfort, incapacitating inflammation, and functional limitations. The conventional approach has involved surgical procedures to eliminate the actively inflamed synovial membrane. This study aims to investigate the recurrence-free survival and functional outcome after synovectomy and subsequent radiosynoviorthesis (RSO) in patients with knee synovitis.

METHODS

Thirty-seven knees diagnosed with pigmented villonodular synovitis (PVNS), rheumatoid arthritis (RA), and peripheral spondyloarthritis underwent synovectomy and subsequent RSO between May 2005 and October 2016. The mean age was 34.9 ± 15.1 years, and the mean follow-up period was 84 ± 36.4 months. Clinical outcomes were assessed using the Oxford Knee Score and the presence of swelling and pain at the last follow-up. Recurrence-free survival denotes the duration from synovectomy to surgical re-synovectomy.

RESULTS

In general, twelve knees underwent re-synovectomy after a mean follow-up of 34.8 ± 24.9 months. The recurrence-free survival was 83.8% at two years, 71.3% at five years, and 61.7% at ten years. The subgroup analysis revealed recurrence-free survival at two years in 63.6% of patients with PVNS, 86.7% of those with RA, and 100% of individuals with peripheral spondyloarthritis.

CONCLUSIONS

This study demonstrates that combined therapy for synovitis is an effective approach, significantly improving clinical outcomes.

Radiosynovectomy in routine care: an old tool with modern applications

Objectives:

Radiosynovectomy can be an effective treatment for difficult-to-treat monoarthritis resistant to systemic and local standard therapy. The objective of our study was to determine predictors of good response to radiosynovectomy in routine care and give an overview of this underused technique.

Methods:

Retrospective observational study of all the patients who underwent radiosynovectomy during a 6-year inclusion period. All the procedures were ultrasound guided and the radiopharmaceutical used was chosen according to joint size. The patient was considered to have an effective response to radiosynovectomy if the attending physician reported a positive outcome and there was no need to increase local and or systemic treatment due to arthritis in the affected joint during the next 12 months following the procedure.

Results:

We included 67 patients who underwent radiosynovectomy in the knee (73.1%), wrist (16.4%), and elbow (10.5%). Overall, 44 (65.7%) procedures were considered effective. In the multivariate analysis, infiltration of wrists (odds ratio = 0.192; confidence interval = 0.046–0.79) and pigmented villonodular synovitis (odds ratio = 0.13; confidence interval = 0.021–0.82) were independently associated with a noneffective response. No patients experienced complications associated with radiosynovectomy during follow-up.

Conclusion:

Infiltrations of wrists with joint damage seem less likely to have a response to radiosynovectomy. In pigmented villonodular synovitis, radiosynovectomy as an adjuvant therapy for relapse might not be effective when performed more than 6 months after surgery. Overall, radiosynovectomy is an effective and safe treatment for persistent monoarthritis.

The EANM guideline for radiosynoviorthesis

Purpose

Radiosynoviorthesis (RSO) using the intraarticular application of beta-particle emitting radiocolloids has for decades been used for the local treatment of inflammatory joint diseases. The injected radiopharmaceuticals are phagocytized by the superficial macrophages of the synovial membrane, resulting in sclerosis and fibrosis of the formerly inflamed tissue, finally leading to reduced joint effusion and alleviation of joint pain.

Methods

The European Association of Nuclear Medicine (EANM) has written and approved these guidelines in tight collaboration with an international team of clinical experts, including rheumatologists. Besides clinical and procedural aspects, different national legislative issues, dosimetric considerations, possible complications, and side effects are addressed.

Conclusion

These guidelines will assist nuclear medicine physicians in performing radiosynoviorthesis. Since there are differences regarding the radiopharmaceuticals approved for RSO and the official indications between several European countries, this guideline can only give a framework that must be adopted individually.

The use of radiosynovectomy in patients with juvenile idiopathic arthritis. Assessment of treatment efficacy and safety

Objectives

The aim of the study was to evaluate the usefulness of knee joint radiosynovectomy (RS) in patients suffering from juvenile idiopathic arthritis (JIA).

Material and methods

One hundred RS procedures performed in 58 patients with JIA in average age 10.4 years were evaluated.

Results

After 6 weeks, a decrease in the number of cases with joint pain from 90.3% to 29%, with joint oedema from 100% to 74.5%, with joint exudate from 100% to 60.6%, with gait disorders from 19.4% to 3.2%, with joint mobility disorders from 51.1% to 26.6% in the RS cases was observed. A reduction of the score in the Colorado scale from 10.9 to 4.66, in the pain visual analogue scale (VAS) from 50 to 10, in the illness VAS assessed by the patient/parent from 69.9 to 32.4, in the illness VAS assessed by the physician from 68.8 to 36.9 was observed. Six months after the RS procedure, a reduction in the number of cases with joint pain from 89.5% prior to the procedure to 29.5%, with oedema from 100% to 58.3%, with exudate from 100% to 46.9%, with gait disorders from 20% to 2.1%, with joint motility disorders from 51.1% to 26.1% was achieved. The score in the Colorado scale was reduced from 10.9 to 4.04, in the pain VAS from 40 to 0, in the illness VAS assessed by the patient/parent from 69.7 to 27.9, in the illness VAS assessed by the physician from 68.8 to 32.4. In ultrasound examinations, the greatest improvement compared to the initial condition was recorded in the 6^th month after the RS. Radiosynovectomy was positively evaluated by parents and patients in 34 anonymous surveys. Early and late observations (average 1473 days) did not show lesions at the isotope injection site, and no neoplastic lesions were observed.

Conclusions

Radiosynovectomy is a valuable therapeutic option for local treatment in patients with JIA.

Radiosynovectomy is effective in thumb basal joint arthritis

OBJECTIVE

Radiosynovectomy (RSO) describes the internal low-dose radiotherapy of the synovia via intra-articular administration of small radioactive particles. Since the introduction of biologics, the main aetiology of arthritic joints for RSO changed to mostly osteoarthritis with concordant change in typically affected joints. Thus, the effect of RSO in thumb basal joint arthritis (BJTh) with focus on osteoarthritis needs to be explored.

DESIGN

From 2017 to 2020, 219 BJTh were treated in 125 patients, 17 patients with rheumatoid arthritis (RA) and 108 patients with osteoarthritis (OA). The therapeutic effect was assessed using a four-step subjective scoring.

RESULTS

20% of the treated joints were symptom free, 48% had a very good response, 16% slight and 16% no response. RSO was performed in 71 patients singularly and in 54 patients repetitively. The mean response duration was 6.8 months with a maximum of 48 months. 35% of patients had post-therapeutic pain relief followed by relapse after 3 months. Response duration showed no significant difference the between first and repetitive therapy, primary responder and primary non-responder and RA and OA.

CONCLUSION

In thumb basal joint arthritis, RSO leads to response rates from 66 to 79%, mean response duration from 6 to 12 months and individual response duration 48 months. The present results are in line with previously published response rates in smaller joints. In respect to 35% of patients with relapse within 3 months post-therapy, we recommend a primary follow-up after 3-4 months.

Prospective Clinical Evaluation of Intra-Articular Injection of Tin-117m (117mSn) Radiosynoviorthesis Agent for Management of Naturally Occurring Elbow Osteoarthritis in Dogs: A Pilot Study

Purpose

To evaluate the clinical effects of an intra-articular injection of ^117mSn-colloid for management of canine grade 1 or 2 elbow osteoarthritis (OA).

Patients and Methods

This was a prospective study in 23 dogs with grade 1 or 2 elbow OA. An orthopedic examination and elbow radiographs were performed to confirm the presence of OA. Dogs were randomly assigned to receive unilateral intra-articular (IA) injection of low-dose (LD: 1.0mCi, n =8), medium-dose (MD: 1.75mCi, n =6), or high-dose (HD: 2.5mCi, n =9) of ^117mSn-colloid. The primary outcome measure was peak vertical force (PVF) from force-plate gait analysis and secondary outcome measures included the Canine Brief Pain Inventory score (CBPI) and elbow goniometry. The CBPI was evaluated at pretreatment and then monthly post treatment for 1 year, and goniometry and PVF were evaluated at pretreatment, and at 1, 3, 6, 9 and 12 months post treatment.

Results

PVF improved at 3, and 9 months compared to pretreatment values in the HD group. CBPI scores improved at most of the time points in all dose groups. There was no significant difference in elbow goniometry between treated and untreated elbows. There were no self-reports of any adverse effects of the injection by the owners and none were noted by the examining veterinarian at the time of regularly scheduled re-evaluations.

Conclusion

^117mSn IA injection was free of any obvious adverse effects, improved CBPI scores, and increased weight bearing in limbs with elbow OA providing preliminary evidence that ^117mSn may be beneficial in the management of elbow OA in dogs. Although ^17mSn appeared to be effective for management of elbow OA in these dogs, this pilot study has inherent limitations; therefore, future studies with larger numbers and with placebo group are needed.

90Y Radiosynovectomy in Persistent Synovitis Caused by Knee Replacement: Long-Term Outcome

INTRODUCTION

After knee replacement, therapy resistant, persistent synovitis is a common issue, which causes effusion and pain, and leads to loosing. It has been hypothesized that radiosynovectomy (RSO) is useful in these patients.

MATERIALS AND METHODS

A cohort of 55 patients with 57 knee replacements and persistent synovitis underwent RSO using 4.9 ± 0.24 mCi (182 ± 9 MBq) of Y-citrate. The number of RSOs ranged from 1 to 4. Bone scans before and 3 months after every RSO were performed. Long-term follow-up ranged from 0.8 to 7.6 years with a mean of 23.2 months. For qualitative analysis, an established 4 steps scoring was used. For quantification, the uptake was determined within the Tc-MDP scintigraphy blood pool phase before and after therapy.

RESULTS

Long-term response was in 27% with excellent, 24% good, 30% weak, and 20% no response. The duration of response was 12.0 ± 12.0 months (maximum, 54 months). In patients with repeated treatment, the effect after the first therapy was lesser than in patients who received a single treatment in total. However, 3 months after the last RSO, patients with repeated treatment showed a similar effectiveness than single treated patients. At the end of long-term follow-up, patients with repeated RSOs had a higher effectiveness at similar duration response. In bone scan, 65% of patients showed a reduction of uptake. When comparing subjective and objective response, 78% of patients showed a concordance in both symptoms and scintigraphy. Pilot histological analysis revealed that the synovitis is triggered by small plastic particles.

CONCLUSIONS

We concluded that RSO is an effective therapy in patients with knee replacement and persistent synovitis with high long-term response. Repeated treatment leads to a stronger long-time response.

Prospective evaluation of phosphorus-32 radiation synovectomy in patients with severe and chronic rheumatoid arthritis unresponsive to conventional medical treatment

OBJECTIVES

To determine the efficacy of Phosphorus-32 radiation synovectomy in the treatment of patients with severe rheumatoid arthritis (RA) unresponsive to systematic or local medical therapy.

METHODS

Twenty-three knees in 16 patients with severe chronic RA were prospectively treated by intra-articular installation of Phosphorus-32 and evaluated at 1, 3, 6, and 12 months. The Western Ontario and McMaster Universities Arthritis index (WOMAC), visual analog scale (VAS), Health Assessment Questionnaire (HAQ), pain scale, and grade of joint effusion and tenderness were assessed. At the 12-month time interval, the treated knees were classified into four categories: excellent response (no symptoms), good response (significant reduction of symptoms), moderate response (slight decrease), and poor response (no change or worsening).

RESULTS

Excellent response or good response was observed in 13/23 (56.5%) of the treated knees, moderate response in 2/23 (8.7%) of the treated knees, and poor response in 8/23 (34.8%) of the treated knees. The grades of effusion and tenderness were significantly decreased one-month posttreatment (P< 0.05); however, these changes did not persist at other time intervals (P > 0.05). There was a significant improvement in the HAQ, WOMAC, VAS, and pain scores at all time points compared with baseline, including at the 12-month time interval (P < 0.05).

CONCLUSION

Phosphorus-32 radiosynovectomy is an effective therapeutic treatment for patients with RA of the knee unresponsive to conventional pharmacotherapy.

Design, synthesis and characterization of hydroxyapatite-chitosan nanocomposite radiolabelled with 153Sm as radiopharmaceutical for use in radiosynovectomy

The aim of the present study was to introduction of hydroxyapatite/chitosan nanocomposite as a new radiosynovectomy agent with excellent properties. In this work, the nanocomposite was prepared through a reliable method and characterized using different techniques to elucidate its chemical structure and physiochemical properties. The prepared nanocomposite was successfully radiolabeled with 153Sm under optimal conditions and with high radiolabelling yield (99 %). The radiochemical purity of the prepared radiopharmaceutical was found to be >99 % as determined by ITLC technique. In vitro stability studies in saline solution and in human serum showed that the radiolabeled nanocomposite retained its stability for at least 6 days. The biodistribution and imaging studies in wild-type rats revealed high retention of the agent into the synovial joints of the knee even at 96 h post-injection, thereby indicating excellent in vivo stability of 153Sm labeled hydroxyapatite-chitosan nanocomposite. Therefore, the prepared radiopharmaceutical would be a potential therapeutic agent for use in radiosynovectomy procedure.

Intraarticular injection of a Tin-117 m radiosynoviorthesis agent in normal canine elbows causes no adverse effects

This longitudinal prospective exploratory study used serial measurements in five dogs to evaluate safety and retention of a tin-117 m (^117m Sn) colloid after intra-articular injection in normal elbow joints. Each dog was deemed healthy based on physical examination, laboratory results, and radiographic evaluation of both elbows. While anesthetized, each received an MRI of both elbows, followed by fluorine-18 fluorodeoxyglucose positron emission tomography scans of both elbow joints and associated lymph nodes. Joint fluid (0.5-1.0 mL) was withdrawn aseptically from the left elbow joint, followed by intra-articular injection of ^117m Sn colloid (92.5 MBq; 1-1.5 ml). Post-injection assessments included blood counts, serum chemistry panels, urinalyses, radiographs, joint fluid analyses, MRI/positron emission tomography scans, scintigraphy, and biodistribution scans. On day 45-47, each dog was euthanized and a complete postmortem examination was performed. Tissue samples were submitted for histopathology and radioisotope retention studies. Left elbow joints were decalcified and sectioned for future autoradiography. Scintigraphy, 1 day after injection, indicated slight radioisotope escape from the joint to regional lymph nodes. Serial blood, urine, feces, and organ counts indicated >99.1% of the ^117m Sn activity was retained in the joint for 45-47 days. Radiation output levels were below patient release levels the day following injection. Maximum standard uptake value for the injected joint decreased. Joint fluid cytology was unchanged. No dog exhibited lameness during the study. Absence of joint damage and lack of systemic effects after injection of the ^117m Sn colloid in normal canine elbow joints indicate that this agent may be safely used for radiosynoviorthesis in dogs with osteoarthritis.

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.

The Efficacy of Yttrium-90 Radiosynovectomy in Patients with Camptodactyly-Arthropathy-Coxa Vara-Pericarditis Syndrome

OBJECTIVE

Camptodactyly-arthropathy-coxa-vara-pericarditis (CACP) syndrome is an autosomal recessive disorder caused by mutations in PRG4 gene that encodes for proteoglycan 4, the main lubricant for joints and tendon surfaces. It is a non-inflammatory arthropathy, characterized by joint effusions and synovial hypertrophy. So far, there is no effective treatment for this disorder. To evaluate the effectiveness of yttrium-90 radiosynovectomy in arthropathy of patients with CACP syndrome.

METHODS

Consecutive patients with CACP syndrome were prospectively evaluated at the enrollment and 3 months after the right knee injection with yttrium-90. The outcome variables were patient/parent and physician's global assessment measured by a 3-point scale, right knee swelling and range of motion on a 3-point scale, in addition to magnetic resonance imaging (MRI) assessment of the right knee for bone, cartilage, fluid, synovial hypertrophy and soft tissue changes.

RESULTS

Six (three boys, three girls) patients with a mean age of 12 years and mean follow-up duration of 8.5 years completed a single right knee intra-articular yttrium-90 injection with 5 mCi. The procedure was well tolerated without adverse events apart from mild and transient joint pain in two patients. There was a minimal radioisotope leakage to soft tissue in two patients. During the 3-month follow-up interval, there was no improvement in the outcome variables. Patients and parents did not notice favorable therapeutic effects and global physician assessment was unsatisfactory. There was no difference in knee joint swelling or range of motion. Furthermore, MRI findings were unchanged. However, there was a minimal increase in synovial fluid post injection.

CONCLUSION

Yttrium-90 radiosynovectomy seems to be a safe and well tolerated procedure, however, it did not show a beneficial therapeutic effect in arthropathy of CACP syndrome with the given dosage and interval. Studies including a larger number of patients and probably repeated injections are needed to derive satisfactory results about the effectiveness of yttrium-90 in CACP syndrome patients.

Radionuclide synovectomy - essentials for rheumatologists

Radionuclide synovectomy is a minimally invasive method of treating persistent joint inflammation. It involves intra-articular injection of radioactive colloids which induce necrosis and fibrosis of hypertrophic synovial membrane. The most common indication for radiosynovectomy is rheumatoid arthritis, although patients with seronegative spondyloarthropathies, unclassified arthritis, haemophilic arthropathy and other less common arthropathies can also benefit from this method. Radiosynovectomy is safe, well tolerated and efficacious. About 70–80% of patients respond well to the therapy. However, the therapeutic effects are considerably worse in patients with co-existent osteoarthritis and advanced joint degeneration. Despite its advantages, radionuclide synovectomy is not performed as often as it could be, so greater knowledge and understanding of this method are needed. The authors present the most important facts about radiosynovectomy that may help rheumatologists in their daily clinical practice.

Therapeutic radionuclides in nuclear medicine: current and future prospects

The potential use of radionuclides in therapy has been recognized for many decades. A number of radionuclides, such as iodine-131 ((131)I), phosphorous-32 ((32)P), strontium-90 ((90)Sr), and yttrium-90 ((90)Y), have been used successfully for the treatment of many benign and malignant disorders. Recently, the rapid growth of this branch of nuclear medicine has been stimulated by the introduction of a number of new radionuclides and radiopharmaceuticals for the treatment of metastatic bone pain and neuroendocrine and other malignant or non-malignant tumours. Today, the field of radionuclide therapy is enjoying an exciting phase and is poised for greater growth and development in the coming years. For example, in Asia, the high prevalence of thyroid and liver diseases has prompted many novel developments and clinical trials using targeted radionuclide therapy. This paper reviews the characteristics and clinical applications of the commonly available therapeutic radionuclides, as well as the problems and issues involved in translating novel radionuclides into clinical therapies.

Radiosynovectomy in the therapeutic management of arthritis

Radiosynovectomy is a well-established therapy in arthritis and involves an intra-articular injection of small radioactive particles to treat a synovitis. In Europe, frequent indications are rheumatoid and poly-arthritis. Especially in Germany radiosynovectomy is the second common therapy in Nuclear Medicine with about 40,000–60,000 treated joints per year. In Spain, USA, Turkey, Argentines and Philippines the therapy is more use in hemophilic arthritis with excellent results. Especially in developing countries with low availability of clotting factors, the radiosynovectomy represent a cost effective therapeutic option for repeated bleedings in hemophilic arthropathy. The special focus in these countries is maintaining of mobility and work ability. Often only the knee and medium joints (ankle, elbow and shoulder) are treated using yttrium-90, rhenium-186 or phosphorus-32. However, in rheumatoid arthritis most common affected joints are the fingers. For the treatment in these small joints, erbium-169 is necessary. Unfortunately, erbium-169 is only available in Europe. Further indications for radiosynovectomy are osteoarthritis and the articular effusion after joint replacement. The reported response rates in rheumatoid and poly-arthritis range from 60% to 80% depends from the stage of previous arthrosis. The best effectiveness of therapy was observed in hemophilic arthritis with response rate of 90% and significant reducing of bleeding frequency. The therapy is well-tolerated with low rate of side effects. In respect of the specific uptake of particles in the synovia and short range of beta radiation, the radiation exposure outside the joint is very low. The radiosynovectomy has efforts in comparison to surgical synovectomy: it's a minor intervention with low costs; and simultaneous treatments of multiple joints or treatment in short intervals are possible. The presented paper summarized the published papers and reports our own experiences in >15,000 treated joints.

Central pathways causing fatigue in neuro-inflammatory and autoimmune illnesses

BACKGROUND

The genesis of severe fatigue and disability in people following acute pathogen invasion involves the activation of Toll-like receptors followed by the upregulation of proinflammatory cytokines and the activation of microglia and astrocytes. Many patients suffering from neuroinflammatory and autoimmune diseases, such as multiple sclerosis, Parkinson's disease and systemic lupus erythematosus, also commonly suffer from severe disabling fatigue. Such patients also present with chronic peripheral immune activation and systemic inflammation in the guise of elevated proinflammtory cytokines, oxidative stress and activated Toll-like receptors. This is also true of many patients presenting with severe, apparently idiopathic, fatigue accompanied by profound levels of physical and cognitive disability often afforded the non-specific diagnosis of chronic fatigue syndrome.

DISCUSSION

Multiple lines of evidence demonstrate a positive association between the degree of peripheral immune activation, inflammation and oxidative stress, gray matter atrophy, glucose hypometabolism and cerebral hypoperfusion in illness, such as multiple sclerosis, Parkinson's disease and chronic fatigue syndrome. Most, if not all, of these abnormalities can be explained by a reduction in the numbers and function of astrocytes secondary to peripheral immune activation and inflammation. This is also true of the widespread mitochondrial dysfunction seen in otherwise normal tissue in neuroinflammatory, neurodegenerative and autoimmune diseases and in many patients with disabling, apparently idiopathic, fatigue. Given the strong association between peripheral immune activation and neuroinflammation with the genesis of fatigue the latter group of patients should be examined using FLAIR magnetic resonance imaging (MRI) and tested for the presence of peripheral immune activation.

SUMMARY

It is concluded that peripheral inflammation and immune activation, together with the subsequent activation of glial cells and mitochondrial damage, likely account for the severe levels of intractable fatigue and disability seen in many patients with neuroimmune and autoimmune diseases.This would also appear to be the case for many patients afforded a diagnosis of Chronic Fatigue Syndrome.