Radiosynovectomy in haemophilic synovitis and arthropathy of the knee: A scoping review.

INTRODUCTION: Radiosynovectomy is an established treatment for chronic synovitis in patients with haemophilia. Although its role in rheumatological diseases has diminished, it remains an accepted therapy for haemophilic synovitis. AIM: The aim of this scoping review was to map and summarise the evidence surrounding radiosynovectomy in haemophilic knees, identify gaps in the literature and inform future research. RESULTS: Forty-three manuscripts and abstracts were identified for this review. Evidence was limited to observational studies and Yttrium-90 was the most studied licensed radioisotope. Radiosynovectomy was associated with a reduction in bleeding frequency and pain, improvements in range of motion and a reduction in the use of factor replacement. CONCLUSION: The literature reviewed lacks studies of sufficient methodological quality to permit systematic review and meta-analysis. Systematic review using risk of bias assessment for observational studies should be undertaken to better evaluate the efficacy and safety of radiosynovectomy. A causal relationship between RSV and key clinical outcomes remains undetermined.

Formulation and In-vivo Characterization of 177Lu-tin-colloid as a Radiosynovectomy Agent.

INTRODUCTION: Arthritis is an inflammatory disorder that affects one or more joints of the body for various reasons, including autoimmune disorders, trauma, or infection. In many cases, traditional long-term treatment with various drug combinations (NSAIDs, diseasemodifying antirheumatic drugs, systemic corticosteroids, etc.) can provide relief, but many joints require additional local treatment. Radiosynovectomy (RSV) is an alternative method to current treatment options. Both the global supply shortage of 90Y in recent years and the increasing use of 177Lu-labeled radiopharmaceuticals in the field of nuclear medicine have made it possible to develop 177Lu-labeled microparticles and test them in small groups as RSV agents. This study aimed to develop the 177Lu labeled tin colloid formulation and demonstrate its invivo characterization. MATERIAL AND METHODS: Particle size, shape, and labelling efficiency of the four formulations developed were determined. The formula with the highest labelling efficiency was selected for further studies. The quality of the formulation was evaluated based on radionuclidic, radiochemical, and microbial purity. In-vitro stability was evaluated by determining the labelling efficiency. In-vitro stability was tested in PBS and synovial fluid. The biological characterization was assessed using SPECT/CT after injecting the formulation into the normal knee joints of the rabbits. RESULTS: Aggregated colloidal particles were spherical with a particle size of <5µm. Labelling efficiency and radiochemical purity were >95 and 97.65% (Rf=0.2), respectively. The formulation was stable in vitro for up to 72 hours, both in PBS and synovial fluid. The formulation was homogeneously distributed in the joint at 0 and 1 hour after injection, and radioactivity- related involvement and inguinal lymph node involvement due to possible leakage were not detected in the late period. No pyrogenic/allergic side effects were observed during this period. CONCLUSION: 177Lu-tin-colloid was successfully prepared under optimized reaction conditions with high binding efficiency and radiochemical purity. The radiolabeled colloid was found to be stable in-vitro both in PBS and synovial fluid at room temperature. Serial PCET/CT images revealed that the activity was completely retained within the synovial cavity, with no activity leakage out of the joint until 48 hours after the injection. With the support of the results from further clinical studies, it may be possible for the formulation to enter clinical use.

Radiosynovectomy of the hip joint - preliminary experience.

Introduction: Radiosynovectomy (RSV) is a minimally invasive method of treating and controlling joint inflammation refractory to conventional pharmacotherapy. It consist in intraarticular injection of radioactive colloids which irradiate the inflamed synovial membrane to cause its subsequent involution. Despite the fact that hip joint involvement is quite common in systemic inflammatory arthropathies, hip joint RSVs are rarely performed. The aim of this paper is to assess to safety and efficacy of hip joint radioisotope treatment. Material and methods: We retrospectively analyzed the effects of 21 hip joint RSVs performed in 14 patients (10 female, 4 male; aged 8 to 79; mean age 48 years). Before the RSV, all the patients underwent clinical and ultrasound examination. The radiosynovectomies were performed using rhenium-186 sulfide under ultrasound guidance. Each patient underwent post-therapeutic scintigraphy to assess intraarticular distribution of the radiopharmaceutical. The effects of the treatment were assessed clinically and ultrasonographically during at least 2 follow-up visits 3 and 6 months after the RSV. Results: In 9 cases, we observed complete resolution of symptoms 3 and 6 months after the RSV. Four patients had only a partial response and required repeated treatment, and all responded well to the second RSV. In 4 patients the treatment had no significant effect, and no repeated treatment attempt was made. All the responders suffered from inflammatory arthropathies; the non-responders had osteoarthritis, with no history of systemic diseases. In all the patients, no significant adverse effects were observed; in particular there were no radiation burns or infections. All post-therapeutic scintigrams showed proper, intraarticular distribution of the radiopharmaceutical. Conclusions: Radiosynovectomy of the hip joint in systemic joint diseases, especially performed using ultrasound-guidance, is a safe and effective treatment modality.

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.

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 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 6th 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.

Knee radiosynovectomy with 153Sm-hydroxyapatite compared to 90Y-hydroxyapatite: initial results of a prospective trial.

INTRODUCTION: Radiosynovectomy (RS) with 90Y-hydroxyapatite (90Y-HyA) aims to control knee hemarthrosis in hemophiliac patients to prevent secondary arthropathy. However, knee RS using 153Sm-hydroxyapatite (153Sm-HyA) is considered less suitable due to the lower average soft tissue range and energy of 153Sm for large joints, such as the knees. PURPOSE: The objective of this investigation was to assess the efficacy and safety of knee RS with 153Sm-HyA, compared to 90Y-HyA. METHODS: Forty patients were prospectively assigned to undergo knee RS with 153Sm-HyA (n = 19) or with 90Y-HyA (n = 21). The frequency of hemarthrosis episodes before and after treatment were compared. RESULTS: After six months of knee RS, 153Sm-HyA and 90Y-HyA promoted a similar reduction of hemarthrosis episodes (50% and 66.7%, respectively). However, after 12 months of knee RS, the reduction of hemarthrosis episodes was significantly (p = 0.037) higher using 153Sm-HyA (87.5%) compared to 90Y-HyA (50.0%). This discrepancy was more pronounced (p = 0.002) for 153Sm-HyA compared to 90Y-HyA in adults/adolescents. CONCLUSION: Knee radiosynovectomy with 153Sm-HyA is safe, reduces hemarthrosis episodes after 12 months of treatments, especially in adults/adolescents and even with grades III/IV arthropathy, similar to 90Y-HyA. 90Y-HyA seems to promote better hemarthrosis control in small children.

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.

Radiosynovectomy is a safe and an efficient alternative in the treatment of chronic, recurrent knee hemarthrosis.

Chronic recurrent hemarthrosis, defined as repeated intra-articular hemorrhage, can lead to a disabling arthropathy. We herein report on a 26-year-old patient presenting with recurrent, postoperative, serious knee hemarthrosis refractory to conventional treatment, including systemic and intra-articular steroid injections as well as chemical synovectomy with osmic acid. The patient was finally treated with a twice performed knee radiosynovectomy with yttrium-90 and showed an extraordinary good clinical outcome with a symptom-free period of 4 years. In cases of refractory hemarthrosis, radiosynovectomy should have a place in the therapeutic armamentarium of the treating physician, as a minimally invasive, safe, and efficient therapeutic tool.

Prognostic factors of radiosynovectomy in haemophilia patients with inhibitors: Survival analysis in a 19-year period.

INTRODUCTION: People with haemophilia (PwH) with inhibitors have an increased risk of bleeding and early development of progressive arthropathy. Radiosynovectomy (RS) has been effective in dramatically reducing the frequency of haemarthroses. In the present study, the mid- and long-term results of the efficacy of RS in PwHs with inhibitors and prognostic factors that influence success and failure of RS were presented. MATERIAL AND METHOD: Radiosynovectomy was performed in 51 joints of 22 PwHs with inhibitors diagnosed with chronic haemophilic synovitis between January 2000 and December 2018. Two patients were lost to follow-up and four joints were excluded. Number of bleeding episodes within the pre- and post-treatment 6 months were documented. Treatment failure was defined as need for repeat RS injection. RESULTS: Results of 47 RS were analysed. The mean bleeding frequency of the joints was 11.2 ± 6.2 (median 9) within the last 6 months in the pre-treatment evaluation. After the treatment, the mean bleeding frequency of the joints decreased to 1.2 ± 2.8 (median 0) for first 6 months (P < .0001). The cumulative survival rate at 12 months was 87% and 78% at 36 months. The receiver operating characteristic (ROC) curve analysis revealed that cut-off points of 12 bleeding episodes within the last 6 months (sensitivity, 71.4; specificity, 81.8 P = .0022) and an inhibitor titre of 63.4 BU (sensitivity, 57.1; specificity, 75.8; P = .31) were threshold levels for a predisposition for failure. CONCLUSION: Radiosynovectomy is an effective and safe intervention in PwHs with inhibitors. Bleeding frequency is a prognostic marker for the success of RS treatment. Patients who have more than 12 bleeding episodes within the last 6 months before the RS treatment have a higher rate of failure.

Complications of hemophilia in the elbow: current management.

INTRODUCTION: After the ankle and knee, the elbow is the most commonly impaired joint in patients with hemophilia. AREAS COVERED: A Cochrane Library and PubMed (MEDLINE) search related to elbow problems in hemophilia was conducted. Early and continuous primary hematological prophylaxis (ideally starting in infancy) is essential, given that the juvenile elbow is highly prone to the musculoskeletal complications of hemophilia. If primary hematological prophylaxis is not administered (due either to lack of affordability or lack of venous access), persistent hemarthrosis can occur in the elbow. Hemarthroses will then require aggressive treatment (through arthrocentesis under factor factor coverage) to prevent progression to synovitis (requiring prompt radiosynovectomy or arthroscopic synovectomy) and ultimately hemophilic arthropathy (requiring rehabilitation and orthopedic surgery). Between the second and fourth decade of life, many patients with hemophilia present elbow joint destruction. EXPERT OPINION: In the initial stage of joint destruction, rehabilitation and intraarticular injections of hyaluronic acid can relieve the symptoms. In the advanced stage of hemophilic arthropathy, however, surgery is necessary. The main surgical procedures currently available are arthroscopic debridement, radial head resection, and total elbow arthroplasty. Transposition of the ulnar nerve and removal of heterotopic ossifications might also be necessary.

The results of 394 consecutive cases of knee joint radiation synovectomy (radiosynoviorthesis) using 90Y.

OBJECTIVE: The aim of this study was to assess the treatment results of 90Y radiation synovectomy for chronic exudative synovitis of knee joints. METHODS: The retrospective data consist of 394 consecutive knee radiation synovectomies performed using 6 mCi (222 MBq) of 90Y. The assessment included 3-point custom pain and joint mobility scale, evaluation of joint's circumference, binary joint's temperature evaluation, patellar ballottement test, indications for puncture and its volume in applicable cases. 21 cases had to be forfeited due to missing data regarding follow-up. RESULTS: The final analysis of 373 treatment procedures performed in 253 patients yielded following results-at 6 months after treatment, 80.9% of the patients reported at least partial pain relief (including 33.3% with complete pain relief), which increased to 86.7% at one year. The pain intensity decreased over time, however, the outcomes were worse in older patients. The probability of pain recurrence was 15% at 6 months, and 28% at one year. It was highest in post-traumatic synovitis, and lowest in pigmented villonodular synovitis. The circumference of the treated knee joints decreased over the course of follow-up, however, the decrease was significantly lower in older patients. The fraction of patients with full knee joint mobility increased from 34.6 to 40.6% at 6 months and 49.2% at one year. The percentage of patients that required articular puncture decreased from 62.8% at baseline to about 35.6% at 6 months, and 32.8% at one year. Positive patellar ballottement was found in 68.5% before treatment and remained at about 40-50% during the course of follow-up. The increased temperature of the joint was reported in 51.2% at baseline and decreased to 33% at 6 months and 28.3% at one year. CONCLUSIONS: (1) Radiation synovectomy is a safe and effective method of treatment in patients with exudative synovitis, however, the pain recurrence rate is significantly higher in post-traumatic exudative synovitis compared to pigmented villonodular, undifferentiated, and rheumatoid arthritis. (2) Our results suggest that older patients have worse treatment results with radiation synovectomy compared to younger patients.

Post-radiosynovectomy imaging utilizing Erbium-169 citrate.

Currently, there is no imaging procedure for radionuclide therapy utilizing Erbium-169 (Er-169). We have recently published the first post-radiosynovectomy imaging of Er-169 citrate in a case report (Farahati et al., 2017). In this study, we performed in-vitro and in-vivo studies to evaluate the feasibility to assess the distribution of Er-169 citrate after radiosynovectomy in fourteen patients with seventeen affected joints treated for refractory chronic synovitis. Post-radiosynovectomy imaging revealed the feasibility of post-radiosynovectomy detection and distribution utilizing Er-169 citrate in all cases. However, additional in-vitro studies including in-vitro imaging, gamma spectrometry and analysis of half-life indicated that emitted gamma-rays of the Ytterbium-169 in the radiopharmaceutical together with bremsstrahlung induced by Er-169 are the imaging source of emitted counts. Post-radiosynovectomy imaging utilizing Er-169 citrate is feasible and should be implemented in the guidelines for theranostics for quality control, patient safety and therapy monitoring.

Preparation and in vitro evaluation of radiolabeled HA-PLGA nanoparticles as novel MTX delivery system for local treatment of rheumatoid arthritis.

Radiosynovectomy is a technique used to decrease inflammation of the synovial tissue by intraarticular injection of a ß-emitting radionuclide, such as 177Lu, which is suitable for radiotherapy due to its decay characteristics. Drug-encapsulating nanoparticles based on poly lactic­co­glycolic acid (PLGA) polymer are a suitable option to treat several arthritic diseases, used as anti-inflammatory drugs transporters of such as methotrexate (MTX), which has been widely used in the arthritis treatment (RA), and hyaluronic acid (HA), which specifically binds the CD44 and hyaluronan receptors overexpressed on the inflamed synovial tissue cells. The 1,4,7,10­Tetraazacyclododecane­1,4,7,10­tetraacetic acid (DOTA) was used as complexing agent of Lutetium-177 for radiotherapy porpoises. The aim of this research was to synthesize 177Lu-DOTA-HA-PLGA(MTX) as a novel, smart drug delivery system with target-specific recognition, potentially useful in radiosynovectomy for local treatment of rheumatoid arthritis. The polymeric nanoparticle system was prepared and chemically characterized. The MTX encapsulation and radiolabelling were performed with suitable characteristics for its in vitro evaluation. The HA-PLGA(MTX) nanoparticle mean diameter was 167.6 nm ±â€¯57.4 with a monomodal and narrow distribution. Spectroscopic techniques demonstrated the effective conjugation of HA and chelating agent DOTA to the polymeric nanosystem. The MTX encapsulation was 95.2% and the loading efficiency was 6%. The radiochemical purity was 96 ±â€¯2%, determined by ITLC. Conclusion: 177Lu-DOTA-HA-PLGA(MTX) was prepared as a biocompatible polymeric PLGA nanoparticle conjugated to HA for specific targeting. The therapeutic nanosystem is based on bi-modal mechanisms using MTX as a disease-modifying antirheumatic drug (DMARD) and 177Lu as a radiotherapeutic component. The 177Lu-DOTA-HA-PLGA(MTX) nanoparticles showed properties suitable for radiosynovectomy and further specific targeted anti-rheumatic therapy.

Outpatient treatment for haemophilic arthropathy with radiosynovectomy: Radiation dose to family members.

One of the key features of good practice in medicine is the doctor-patient communication. Radiation protection standards for radiosynovectomy (RS) is limited. Yttrium-90 is a beta-emitting radioisotope used in RS to treat joint pain from haemophilic arthritis. ICRP 94 states that if a patient is treated with up to 200 MBq, there is no need for further precautions when it comes to public exposure, however, activities can go up to 370 MBq in RS for the knee. This study analysed 119 family members' safety (16.7% pregnant women). The ambient dose equivalent rate was measured within four distances. A survey was carried analysing risk groups and time spent next to patients. Results showed that family members should be advised to remain at 1.0 m from the patient to decrease accumulated dose by 97.6%. The dose per activity factors estimated in this study is also a useful tool during the risk assessment and doctor/patient communication. Pamphlets were distributed with radiation protection recommendations. Ambient dose equivalent was low enough to show that RS is a safe procedure for family members, which is essential to promote adherence to RS in countries where it is needed but not performed due to lack of information on radiation safety.

Radiosynovectomy in haemophilia.

Radiosynovectomy (RS) is a simple, effective and safe procedure for the control of haemophilic synovitis that causes repetitive haemarthrosis. It must be done after confirming clinically (hard and painless mass on palpation) and by ultrasonography the existence of synovitis in a joint with recurrent haemarthrosis. RS should be the first invasive option (instead of arthroscopic synovectomy) for treatment of chronic synovitis. The technique is highly cost effective in comparison to arthroscopic synovectomy. The indication for RS is the presence of repeated haemarthroses associated with synovitis (confirmed clinically and by imaging techniques) that cannot be controlled by means of haematological treatment. No increase in the risk of cancer has been published and the dose of radiation utilized in RS is minimal. In haemophilic patients with recurrent haemarthrosis, RS should be performed under factor coverage as soon as possible, once the existence of synovitis has been confirmed by ultrasonography. RS should really be considered as a useful adjunctive procedure to the primary intervention, which is intensive replacement therapy.

Remote arterial vasculitis as a possible complication of Phosphorus-32 Radiosynovectomy.

Patients with hemophilia suffer from repeated episodes of hemarthrosis leading to chronic inflammation and synovitis. Radiosynovectomy is an effective nonsurgical modality that can reduce inflammation, pain, and hemarthrosis in such cases. We describe an adolescent male with severe Hemophilia A, who developed arterial vasculitis and perivasculitis targeting the brachiocephalic, right common carotid, and right subclabvian arteries occurring within few days after difficult Phosphorus-32 radiosynovectomy, possibly as a complication of the procedure. Despite prophylaxis with recombinant FVIII therapy, he developed chronic synovitis and underwent radionuclide synovectomy with P-32 injection to the left ankle and right knee. Five days later, he developed pain in the lower right neck and right upper chest. Computed tomography and magnetic resonance imaging and angiography demonstrated inflammation involving the arteries of the right thoracic inlet. Geiger-Mueller meter indicated increased radioactivity not only in the left ankle and right knee but also in the right upper chest. Detection of radioisotope at the right thoracic inlet corresponding to the area of vasculitis was indicative of likely deposition of the P-32 isotope in an area exposed to maximum cardiac output and increased blood flow, leading to subclavian, carotid, and innominate arteritis with surrounding edema.

Beta burns following radionuclide synovectomy.

Radionuclide synovectomy (RSV) is a form of minimally invasive treatment of persistent joint inflammation. The procedure has a high safety profile and the occurrence of serious adverse events, such as full-thickness skin radiation necrosis, is rare. Less severe radiation events, while more common, are usually benign and self-limiting. We present two cases of low-grade beta burns that developed after RSV, despite proper injection technique. The potential long-term risk of such exposure is also discussed, with reference to historical radiation incidents. While low-grade beta burns after RSV usually pose little danger to the patient, any clinician involved in radionuclide treatment of arthritis should be aware of their existence and management.