Yttrium90 synovectomy in the management of chronic knee arthritis: a single institution experience

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.

Radiation Safety and Accidental Radiation Exposures in Nuclear Medicine

Medical radiation accidents and unintended events may lead to accidental or unintended medical exposure of patients and exposure of staff or the public. Most unintended exposures in nuclear medicine will lead to a small increase in risk; nevertheless, these require investigation and a clinical and dosimetric assessment. Nuclear medicine staff are exposed to radiation emitted directly by radiopharmaceuticals and by patients after administration of radiopharmaceuticals. This is particularly relevant in PET, due to the penetrating 511 keV γ-rays. Dose constraints should be set for planning the exposure of individuals. Staff body doses of 1-25 µSv/GBq are reported for PET imaging, the largest component being from the injection. The preparation and administration of radiopharmaceuticals can lead to high doses to the hands, challenging dose limits for radionuclides such as ⁹⁰Y and even ¹⁸F. The risks of contamination can be minimized by basic precautions, such as carrying out manipulations in purpose-built facilities, wearing protective clothing, especially gloves, and removing contaminated gloves or any skin contamination as quickly as possible. Airborne contamination is a potential problem when handling radioisotopes of iodine or administering radioaerosols. Manipulating radiopharmaceuticals in laminar air flow cabinets, and appropriate premises ventilation are necessary to improve safety levels. Ensuring patient safety and minimizing the risk of incidents require efficient overall quality management. Critical aspects include: the booking process, particularly if qualified medical supervision is not present; administration of radiopharmaceuticals to patients, with the risk of misadministration or extravasation; management of patients' data and images by information technology systems, considering the possibility of misalignment between patient personal data and clinical information. Prevention of possible mistakes in patient identification or in the management of patients with similar names requires particular attention. Appropriate management of pregnant or breast-feeding patients is another important aspect of radiation safety. In radiopharmacy activities, strict quality assurance should be implemented at all operational levels, in addition to adherence to national and international regulations and guidelines. This includes not only administrative aspects, like checking the request/prescription, patient's data and the details of the requested procedure, but also quantitative tests according to national/international pharmacopoeias, and measuring the dispensed activity with a calibrated activity meter prior to administration. In therapy with radionuclides, skin tissue reactions can occur following extravasation, which can result in localized doses of tens of Grays. Other relevant incidents include confusion of products for patients administered at the same time or malfunction of administration devices. Furthermore, errors in internal radiation dosimetry calculations for treatment planning may lead to under or over-treatment. According to literature, proper instructions are fundamental to keep effective dose to caregivers and family members after patient discharge below the Dose constraints. The IAEA Basic Safety Standards require measures to minimize the likelihood of any unintended or accidental medical exposures and reporting any radiation incident. The relative complexity of nuclear medicine practice presents many possibilities for errors. It is therefore important that all activities are performed according to well established procedures, and that all actions are supported by regular quality assurance/QC procedures.

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.

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.

Development of 186/188Re-Chitosan as an Effective Therapeutic Agent for Rheumatoid Arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an inflammatory chronic disease characterized by inflammation, pain, swelling and disability, and radiosynovectomy is one of the disease treatment lines. In this study, the possibility of providing rhenium-186/rhenium-188 chitosan radiopharmaceuticals, optimization of conditions for their production and bio-distribution are reported.

OBJECTIVE

In order to build perrhenic acid for labeling, natural rhenium was exposed to radiation. Radionuclidic and radiochemical purities of (186/188Re)-NaReO4 were examined by gamma spectroscopy and paper chromatography methods, respectively.

METHODS

Labeling of chitosan with rhenium was done in different acidic situations. The radiochemical purity 186/188Re-chitosan was applied by radio thin layer chromatography (RTLC). Lastly, the bio-distribution of the radiolabeled chitosan was studied in various organs after intra articular injection of the complex to lab rats. Gamma spectrometry confirmed the high rhenium radionuclidic purity. Chromatography results showed that perrhenic acid was produced with purity greater than 97% and rhenium chitosan labeling was done over 98% in pH = 3. Dissection results showed a high bio-distribution of 186/188Re-chitosan after injection into the joint with no leakage to surrounding organs.

CONCLUSION

According to the results, there is a possibility of labeling rhenium with chitosan in very high radiochemical purity. Regarding the high retention of these radiopharmaceuticals in joints with no leakage to surrounding organs, 186/188Re-chitosan can be applied as new radiosynovectomy drugs for rheumatoid arthritis treatment.

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.

Persistent cutaneous ulcers after Yttrium-90 synovectomy, an unusual complication: two case reports and a review of the literature

Development of persistent deep cutaneous ulceration is a rare and serious complication of radiosynovectomy, an extended procedure used in the treatment of chronic synovitis. Cutaneous radiation necrosis is a rare complication of synovectomy, probably as a result of radiocolloid para-articular injection. This rare phenomenon should be suspected when an ulcer adjacent to an articulation appears several days or even months after a radiation synovectomy. It can turn into a challenging diagnosis for rheumatologists, orthopaedists and dermatologists, especially in those cases with a late development of the skin lesions. Recognition of this potential side effect is important in order to establish a proper therapeutic strategy and avoid unnecessary treatments. Surgical excision appears to be the treatment of choice. We report two patients with knee osteoarthritis treated with intra-articular injection of Yttrium-90 who developed persistent cutaneous ulcers secondary to radiation necrosis.

Comparison of arthroscopic, radioactive and combined synovectomy in the treatment of chronic non-specific knee synovitis

OBJECTIVE

To compare the outcomes of arthroscopic, radioactive and combined synovectomies in patients with chronic non-specific recurrent synovitis who did not respond to conservative therapy.

SUBJECTS AND METHODS

Twenty-nine patients enrolled between 2007 and 2011 were divided into 3 groups: group 1 was treated with arthroscopy, group 2 received a radioactive drug and group 3 received a combined (radioactive and arthroscopic) synovectomy. Treatment efficacy was evaluated by comparing pre- and post-operative Lysholm knee scores (LKS), night pain, resting pain, activity pain and effusions using visual analogue scales (VAS). Patient satisfaction was assessed using the visual analogue patient satisfaction scale (VAPSS).

RESULTS

The mean age of the study participants was 41.5 ± 5.2 years (range 14-76), and the mean follow-up period was 33.6 ± 3.2 months (range 17-78). Before treatment, the mean LKS was 41.4 ± 3.4 in group 1, 39.6 ± 3.3 in group 2 and 37.1 ± 4.6 in group 3. After treatment, the corresponding mean LKS were 77.7 ± 2.1, 81.6 ± 2.8 and 91.3 ± 2.7 in groups 1, 2 and 3, respectively; the increase was statistically significant (p < 0.05). The VAS scores before and after treatment decreased significantly (p < 0.05). The mean VAPSS score, a measure of patient satisfaction, was 5.1 ± 1.7, 5.8 ± 1.5 and 7.4 ± 1.8 in groups 1, 2 and 3, respectively, and the difference between groups 1 and 2 was not statistically significant, while that between group 3 and the other two groups was significant (p < 0.05).

CONCLUSION

This study showed that the three methods used in individuals with chronic non-specific recurrent synovitis were effective; however, arthroscopic synovectomy in combination with radioactive synovectomy was more effective than the other methods and superior in terms of patient satisfaction.

Treatment of skin necrosis after radiation synovectomy with yttrium-90: a case report

Chronic synovitis, unresponsive to systemic medical therapy including agents, anti-inflammatory drugs and remission-inducing agents, and intra-articular administration of corticosteroids can be treated with surgical, chemical and radiation synovectomy. We reported a case of a 23 years old male. Skin radiation necrosis (4 x 5 cm) developed after an injection of Yttrium-90 (Y-90). Full-thickness skin graft had been applied but we were not able to succeed. Skin radiation necrosis was treated with Limberg's flap. As a result we recommend flap surgery instead of skin graft in skin radiation necrosis.

Role of radiosynovectomy in the treatment of rheumatoid arthritis and hemophilic arthropathies

Radiosynovectomy is a novel method of treatment for several acute and chronic inflammatory joint disorders. A small amount of a beta-emitting radionuclide is injected into the affected joint delivering a radiation dose of 70 to 100 Gy to the synovia. The proliferative tissue is destroyed, secretion of fluid and accumulation of inflammation causing cellular compounds stops and the joint surfaces become fibrosed, providing long term symptom relief. The radionuclides are injected in colloidal form so that they remain in the synovium and are not transported by lymphatic vessels causing radiation exposure to other organs. Complete reduction of knee joint swelling has been seen in above 40% and pain relief in 88% of patients. Wrist, elbow, shoulder, ankle and hip joints showed significant improvement in 50-60% and restoration of normal function and long term pain relief has been achieved in about 70% of small finger joints. In hemophilic arthropathies complete cessation of bleeding in about 60% and improved mobility in 75% of patients has been reported.

The intra-articular distribution of 90yttrium does not influence the clinical outcome of radiation synovectomy of the knee

OBJECTIVES

To assess the impact of the intra-articular distribution of (90)yttrium-citrate ((90)Y) on the clinical effect of radiosynoviorthesis (RSO) of the knee and on (90)Y leakage from this joint.

METHODS

Patients with arthritis of the knee received 185 MBq (90)Y combined with a glucocorticoid, followed by clinical bed rest. Intra-articular (90)Y distribution, measured with a dual-head gamma camera immediately or after 24 hours, was scored as mainly diffuse or mainly focal. Leakage to regional lymph nodes, the liver and spleen was assessed with a dual-head gamma camera after 24 hours. Clinical effect was scored after 6 months by a composite change index (CCI), range 0-12; responders were defined as having a CCI > or =6.

RESULTS

Seventy-eight knees of 69 patients, mostly suffering from undifferentiated arthritis (42%) or RA (28%), were treated. (90)Y distribution was mainly diffuse in 54% and mainly focal in 46% with clinical response rates of 40% versus 56%, respectively, p = 0.3. CCI was not correlated with distribution. (90)Y leakage was found only to the liver and the spleen (mean leakage 0.4% and 1.1%, respectively). Leakage was significantly less in case of diffuse intra-articular (90)Y distribution, whereas leakage to the liver was correlated with distribution (r = 0.68, p<0.001). (90)Y leakage was not correlated with CCI.

CONCLUSIONS

Intra-articular (90)Y distribution does not influence the clinical effect of RSO of the knee. Although (90)Y leakage from the joint is less if (90)Y distributes diffusely in the joint cavity, leakage does not seem to hamper the clinical effect.