Evidence-based guideline of the European Association of Nuclear Medicine (EANM) on imaging infection in vascular grafts

Abstract

Purpose Consensus on optimal imaging procedure for vascular graft/endograft infection (VGEI) is still lacking and the choice of a diagnostic test is often based on the experience of single centres. This document provides evidence-based recommendations aiming at defining which imaging modality may be preferred in different clinical settings and post-surgical time window. Methods This working group includes 6 nuclear medicine physicians appointed by the European Association of Nuclear Medicine, 4 vascular surgeons, and 2 radiologists. Vascular surgeons formulated 5 clinical questions that were converted into 10 statements and addressed through a systematic analysis of available literature by using PICOs (Population/problem–Intervention/Indicator–Comparator–Outcome) strategy. Each consensus statement was scored for level of evidence and for recommendation grade, according to the Oxford Centre for Evidence-based Medicine criteria. Results Sixty-six articles, published from January 2000 up to December 2021, were analysed and used for evidence-based recommendations. Conclusion Computed tomography angiography (CTA) is the first-line imaging modality in suspected VGEI but nuclear medicine modalities are often needed to confirm or exclude the infection. Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) has very high negative predictive value but it should be performed preferably at least 4 months after surgery to avoid false positive results. Radiolabelled white blood cell (WBC) scintigraphy, given its high diagnostic accuracy, can be performed at any time after surgery. Preamble The European Association of Nuclear Medicine (EANM) is a professional no-profit medical association that facilitates communication worldwide between individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985. EANM members are physicians, technologists, and scientists specializing in the research and practice of nuclear medicine. The EANM will periodically define new guidelines for nuclear medicine practice to help advance the science of nuclear medicine and to improve the quality of service to patients throughout the world. Existing practice guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated. Each practice guideline, representing a policy statement by the EANM, has undergone a thorough consensus process in which it has been subjected to extensive review. The EANM recognizes that the safe and effective use of diagnostic nuclear medicine imaging requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guideline by those entities not providing these services is not authorized. These guidelines are an educational tool designed to assist practitioners in providing appropriate care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the EANM suggests caution against the use of the current consensus document in litigation in which the clinical decisions of a practitioner are called into question. The ultimate judgement regarding the propriety of any specific procedure or course of action must be made by the physician or medical physicist in the light of all the circumstances presented. Thus, there is no implication that an approach differing from the consensus document, standing alone, is below the standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the consensus document when, in the reasonable judgement of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the consensus document. The practice of medicine includes both the art and the science of the prevention, diagnosis, alleviation, and treatment of disease. The variety and complexity of human conditions make it impossible to always reach the most appropriate diagnosis or to predict with certainty a particular response to treatment. Therefore, it should be recognized that adherence to this consensus document will not ensure an accurate diagnosis or a successful outcome. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources, and the needs of the patient, to deliver effective and safe medical care. The sole purpose of this consensus document is to assist practitioners in achieving this objective.

Radiometal chelators for infection diagnostics

“…Chelator development for 89 Zr and 64 Cu will also enrich the number of PET tracers for infection diagnostics. Moreover, novel chelators for PET radiometals such as 44 Sc and 86 Y could develop new infection-specific tracers via bioconjugation of peptides and antibodies, and based on their PK/PD could be further developed for specific type of infection (e.g., location of infection, type of pathogens).…”

“…Although these imaging techniques lack proper specificity of pathogen detection, they are recommended in the diagnostic workup of infections. For VGI, the current gold standard in European Society of Vascular Surgery guidelines is 18FDG PET/CT or SPECT due to the better sensitivity and specificity (86,87). Table 3 summarizes use of current infection diagnostics, their application and limitation.…”

Radionuclide Imaging of Cytotoxic Immune Cell Responses to Anti-Cancer Immunotherapy

“…T technique is commonly used in clinical practice as it does not require the modification the cells. [ 111 In]In-oxine, [ 89 Zr]Zr-oxine and [ 18 F]FDG have been used for this purp among others (Table 1) [37][38][39]. However, a major drawback of this method is that tracer is diluted with every cell division, diminishing the measurable signal per cell [ Direct ex vivo labelling of immune cells consists of labelling of cells with an agent that remains trapped within the cells, followed by injection of the cells to the patient.…”

“…This technique is commonly used in clinical practice as it does not require the modification of the cells. [ 111 In]In-oxine, [ 89 Zr]Zr-oxine and [ 18 F]FDG have been used for this purpose among others (Table 1) [37][38][39]. However, a major drawback of this method is that the tracer is diluted with every cell division, diminishing the measurable signal per cell [32].…”

Infection-specific PET imaging with 18F-fluorodeoxysorbitol and 2-[18F]F-ρ-aminobenzoic acid: An extended diagnostic tool for bacterial and fungal diseases

“…[ 18 F]FDG is a PET radiotracer that is widely used in the diagnosis and follow-up of tumors and degenerative diseases of the central nervous system ( Dubois et al, 2014 ; Rowe and Pomper, 2021 ; Guedj et al, 2022 ). Conventional in vivo nuclear imaging using radiolabeled monocytes ( Chakfé et al, 2020 ; Erba and Slart, 2020 ) or positron emission tomography (PET) with 2-deoxy-2[ 18 F]fluoro-ᴅ-glucose ([ 18 F]FDG) can provide a rapid diagnosis of difficult-to-diagnose infections (endocarditis, vascular graft infection, and prosthetic joint infection) and at the same time avoid invasive sampling procedures ( Kwee et al, 2008 ; Habib et al, 2015 ; Mahmood et al, 2019 ; Haidar and Singh, 2022 ; Lauri et al, 2022 ). [ 18 F]FDG is an extensively available radiotracer that can be obtained from a cyclotron center and shipped to the hospital because of the long half-life of 18 F (110 min).…”