Besilesomab 1mg kit for radiopharmaceutical preparation

Abstract Background Infection imaging plays a crucial role in clinical decision making, guiding antibiotic therapy and surgical management. Nuclear medicine offers molecular level approaches using three main techniques: [18F]FDG PET/CT, radiolabelled white blood cell (WBC) scintigraphy, and anti-granulocyte monoclonal antibody scintigraphy with [99mTc]Tc-besilesomab. Among these, [99mTc]Tc-besilesomab was developed to simplify infection imaging compared with in vitro WBC labelling, improving accessibility for hospitals without cell-labelling facilities. However, its use is restricted by the need for prior testing for human anti-mouse antibodies (HAMA) to prevent hypersensitivity reactions. Main body In recent years, significant regulatory changes in the European framework for in vitro diagnostics (IVDR 2017/746) have coincided with the withdrawal of the quantitative HAMA enzyme-linked immunosorbent assay from the market and its replacement with a qualitative rapid test. Although this shift aimed to streamline in vitro testing procedures, it has complicated the interpretation of HAMA results and raised concerns about diagnostic accessibility. In some centres, an increase in positive results has been observed with rapid tests, suggesting that patients may be inappropriately excluded from [99mTc]Tc-besilesomab imaging. This situation highlights a paradox: a radiopharmaceutical designed to improve accessibility is now constrained by regulatory and methodological factors. The issue also reflects a broader challenge in nuclear medicine, ensuring patient safety and compliance without limiting access to essential diagnostic tools. Conclusion This debate argues that restoring accessibility to [99mTc]Tc-besilesomab immunoscintigraphy requires both technological and regulatory innovation. Developing quantitative point-of-care HAMA assays, promoting humanised or nanobody-based tracers, and establishing harmonised European guidelines could help balance patient safety with diagnostic availability. The [99mTc]Tc-besilesomab case exemplifies how well-intentioned regulatory transitions may have unintended consequences, underscoring the need for a pragmatic equilibrium between innovation, safety, and accessibility in infection imaging.

Abstract licence: CC BY-NC-ND 4.0

Early and accurate diagnosis of osteomyelitis, an inflammatory process of the bone caused by an infective microorganism, is essential for rapid management of the disease by antimicrobial and/or surgical intervention. Historically, diagnosis has been achieved by histological examination, but, more recently, sophisticated molecular imaging techniques (including computed tomography (CT), magnetic resonance imaging, positron emission tomography, single photon emission CT, scintigraphy) that are increasingly used to support diagnoses made from histological data have been reported. For example, scintigraphy has been used to visualize the inflammatory process in vivo using either radiolabeled leukocytes or radiolabeled antigranulocyte monoclonal antibodies (MAbs). Typically, radiolabeling is achieved using technetium-99m (radioactive half-life = 6.02 hours), and the most commonly used MAbs are the Fab fragment of the immunoglobulin (Ig)G antibody directed against the glycoprotein cross-reactive antigen-90 (sulesomab) and an IgG antibody against normal cross-reactive antigen-95 (BW 250/183, besilesomab (Scintimun ® )). The aim of the present review is to

Abstract licence: CC BY-NC 3.0

Infective endocarditis displays a serious condition with high mortality rates. Establishing a reliable diagnosis can be challenging. This study evaluates granulocyte imaging with 99mTc-Besilesomab-SPECT/CT in order to determine the clinical value of the method and its possible redefinition through the addition of hybrid imaging. The study comprises 26 consecutive patients with suspected infectious endocarditis or prosthetic valve infection that underwent 99mTc-Besilesomab-SPECT/CT in our facility between December 2016 and September 2018. 99mTc-Besilesomab-SPECT/CT images were reviewed by two independent and blinded observers and results were evaluated by transesophageal echocardiography (TEE) and blood culture results as well as by pathological, bacteriological, and clinical findings. Target-to-Background-Ratios were calculated for semi-quantitative analysis. 13/26 patients were in a post-surgical stage. 99mTc-Besilesomab-SPECT/CT was positive in 6 cases. All 6 cases were true positive confirmed by pathological or clinical findings according to the modified Duke Criteria for infective endocarditis. Remaining 19/26 cases were true negative. Target-to-Background ratios were significantly higher in patients that were visually scored positive compared to negative cases. Inter-observer agreement was very good of deciding whether a scan was positive or negative. Sensitivity of 99mTc-Besilesomab-SPECT/CT was 86–100% and specificity was 100%. 99mTc-Besilesomab-SPECT/CT is a useful imaging method for the diagnosis of endocarditis, especially in difficult cases with prosthetic valves or cardiac devices and inconclusive findings in echocardiography. The added value of SPECT/CT was mainly finding and localizing increased uptake at a certain valve, prosthesis, or device cable.

Abstract licence: CC BY 4.0