The role of 99mTc-labelled glucosamine (99mTc-ECDG) in the evaluation of rheumatic joint disease: a screening experience

The Biodistribution and Utility of 99mTc-Ethylenedicysteine-Deoxyglucose (99mTc-Glucosamine) in the Identification of Active Disease in Patients with Rheumatoid Arthritis-a Single Center Prospective Study

Purpose

Our objectives were to investigate the utility of 99mTc-ethylenedicysteine-deoxyglucose (ECDG) in identifying active disease in the joints of patients with rheumatoid arthritis (RA), as well as to evaluate the biodistribution of this radiopharmaceutical.

Methods

A prospective study was conducted at the Department of Nuclear Medicine of the University of the Free State/Universitas Academic Hospital in Bloemfontein, South Africa. Twenty-two participants from the rheumatology department diagnosed with RA according to the ACR/EULAR classification criteria were enrolled. Participants were injected with 20-25 mCi of 99mTc-ECDG. Flow, blood pool, whole body, delayed static, and SPECT/CT images were acquired. Known sites of disease were qualitatively assessed for intensity of uptake, and disease severity was graded (Grade 0-3).

Results

Twenty-two participants were studied. The median (interquartile range) age was 59 (49-68) years, and the majority (n = 21; 95.5%) were females. There was abnormal increased uptake of 99mTc-ECDG noted in majority of the sites of known disease, including unknown sites. SPECT/CT imaging localized radiotracer uptake specifically to the synovial space. Similar biodistribution of radiotracer was noted in all patients, irrespective of disease severity or fasting status.

Conclusion

99mTc-ECDG can efficiently assess disease activity in the joints of patients with RA. It accumulates in sites of both clinical and subclinical disease and might be a very useful tool for the rheumatologist in the management of patients with RA.

The prognostic value of 99m Tc-glucosamine imaging in patients with rheumatoid arthritis: a single center prospective study

OBJECTIVES

Poor prognostic factors in rheumatoid arthritis (RA) are associated with a more severe form of the disease. Nuclear medicine functional imaging has shown remarkable merit at identifying active disease in patients with RA and is increasingly being used in this regard. However, its prognostic value has not been evaluated thoroughly. We aimed to assess the prognostic value of technetium-99m ( 99m Tc-) glucosamine imaging in patients with RA.

METHODS

Twenty-two participants diagnosed by an experienced rheumatologist with RA were recruited for inclusion in the study. Blood samples were obtained from each participant for baseline C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody titer. On the same day, each participant was injected with 20-25 millicurie (mCi) of 99m Tc-glucosamine. Planar and single-photon emission computed tomography images of known disease sites were acquired up to 2 hours after radiopharmaceutical administration. Affected joints were qualitatively assessed and graded for 99m Tc-glucosamine uptake and compared with blood results.

RESULTS

All participants affected joints had an increased uptake of the radiopharmaceutical, with 14 (63.6%) having elevated RF and anti-CCP antibody titers. Eight of the 14 patients with increased RF and anti-CCP antibodies had grade 3 uptake of 99m Tc-glucosamine. The remaining 6 had grade 2 uptake. A significant correlation between higher grade uptake and increased levels of RF and anti-CCP antibodies ( P  = 0.031) was observed.

CONCLUSION

We found a strong correlation between high-grade disease on imaging and the presence of RF and anti-CCP antibodies in patients with RA.

Novel tracers for molecular imaging of interstitial lung disease: A state of the art review

Interstitial lung disease is an overarching term for a wide range of disorders characterized by inflammation and/or fibrosis in the lungs. Most prevalent forms, among others, include idiopathic pulmonary fibrosis (IPF) and connective tissue disease associated interstitial lung disease (CTD-ILD). Currently, only disease modifying treatment options are available for IPF and progressive fibrotic CTD-ILD, leading to reduction or stabilization in the rate of lung function decline at best. Management of these patients would greatly advance if we identify new strategies to improve (1) early detection of ILD, (2) predicting ILD progression, (3) predicting response to therapy and (4) understanding pathophysiology. Over the last years, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have emerged as promising molecular imaging techniques to improve ILD management. Both are non-invasive diagnostic tools to assess molecular characteristics of an individual patient with the potential to apply personalized treatment. In this review, we encompass the currently available pre-clinical and clinical studies on molecular imaging with PET and SPECT in IPF and CTD-ILD. We provide recommendations for potential future clinical applications of these tracers and directions for future research.

99mTc-labelled glucosamine in the assessment of systemic sclerosis inflammatory lung disease: a novel inexpensive investigative tool with predictive value

OBJECTIVE

To evaluate the role of 99mTc-labelled glucosamine [99mTc-ECDG] as a clinical biomarker for the early detection of interstitial lung disease (ILD) in systemic sclerosis (SSc).

METHODS

In this prospective pilot study, glucosamine scanning (GS) was performed in 15 SSc patients, with and without ILD. Collected data included patient disease characteristics, autoantibody profile, GS results, high-resolution computerised tomography [HRCT], pulmonary function tests [PFT], and transthoracic echocardiogram [TTE]. Glucosamine results were correlated with patient clinical profile, HRCT, and PFT's findings.

RESULTS

Lung uptake of 99mTc-ECDG was high in 4 patients, moderate in 3, mild in 5, and normal in 3 with SSc, respectively. Of the patients with high and moderate uptake there was a 100% correlation between 99mTc-ECDG uptake and HRCT showing ILD. Of the 5 patients with mild 99mTc-ECDG uptake, 4 patients had aspiration pneumonia, and 1 had early ILD using HRCT. Of the 3 patients with normal 99mTc-ECDG, 2 had normal HRCTs; the third had severe pulmonary arterial hypertension with minimal HRCT changes of ILD. High and moderate 99mTc-ECDG lung uptake predicted abnormal PFT's in 100% of cases. In 3 patients, there was less extensive disease depicted on the 99mTc-ECDG scans than on the HRCT. These patients demonstrated a more favourable outcome than would have been expected from the HRCT scans alone. Mild 99mTc-ECDG lung uptake correlated with abnormal PFT's in 60% of cases. The pattern of 99mTc-ECDG uptake was excellent (100%) at distinguishing metabolically active ILD from aspiration pneumonia. Diffuse uptake was noted in the former and patchy uptake in the latter disease entity.

CONCLUSION

Increased 99mTc-ECDG uptake in scleroderma lung correlated positively with both structural and functional changes. 99mTc-ECDG is a useful adjunct helping elucidate inflammation secondary to aspiration pneumonia and/or other causes of abnormal PFT's.

Evaluating disease activity in patients with ankylosing spondylitis and rheumatoid arthritis using 99mtc-glucosamine

OBJECTIVE

To evaluate the clinical utility of a novel radiotracer, ^99mTc-glucosamine, in assessing disease activity of both rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Material and Methods: Twenty-five patients with RA (nine males and 16 females) and 12 patients with AS (all male) at various stages of disease were recruited for the study. A clinical history and examination was performed, followed by the measurement of hematological, biochemical, and autoimmune serological parameters to assess disease activity. ^99mTc-glucosamine was intravenously administered and scans were compared with other imaging modalities, including plain X-ray, magnetic resonance imaging (MRI), and bone scans.

RESULTS

In patients with AS, ^99mTc-glucosamine scans were more capable of identifying active disease and differentiating between inflammatory and non-inflammatory causes. In patients with RA, ^99mTc-glucosamine accumulated at all known sites of disease involvement. Uptake was most pronounced in patients with active untreated disease. The relative tracer activity in the involved joints increased with time compared with that in the adjoining soft tissue, liver, and cardiac blood pool. Using Spearman's correlation coefficient, there was a positive correlation among glucosamine scan scores, C-reactive protein (p=0.048), and clinical assessment (p=0.003), which was not noted with bone scans.

CONCLUSION

The radiotracer was well tolerated by all patients, with no adverse reactions. ^99mTc-glucosamine imaging could detect spinal inflammation in AS. With respect to RA, ^99mTc-glucosamine was a viable alternative to ^99mTc-labeled methylene diphosphonate nuclear bone scans for imaging inflamed joints and had the added advantage of demonstrating a significant clinical correlation between disease activity and scan findings.