Editorial Highlights Science and Clinical Applications of Total Body PET

An editorial in Frontiers in Nuclear Medicine introduces a research topic devoted to total body PET, gathering six studies that test the scanner’s capabilities in oncology, muscle perfusion, brain imaging, quality control, automated reporting and an entirely new imaging contrast. The collection is edited by Charalampos Tsoumpas, Laura Providência, Andor W. J. M. Glaudemans, Riemer H. J. A. Slart and Adriaan A. Lammertsma, all of the Department of Nuclear Medicine and Molecular Imaging at University Medical Center Groningen in the Netherlands.

Dynamic PET requires an arterial input function. Traditionally this has meant arterial blood sampling, a procedure that is invasive, technically demanding and unattractive for routine clinical use. The editorial notes that this requirement has limited the clinical translation of quantitative PET, and several of the collected studies attack the problem from different angles.

The first of these, by Smith and colleagues, validated image-derived input functions for dynamic fluorine-18 fluorodeoxyglucose studies on a long axial field of view PET/CT system in eleven oncology patients. The team concluded that an input function derived from the aorta provides a reliable alternative to manual blood sampling. A previous study showed that kinetic parameters obtained using a carotid artery image-derived input function produced unreliable results compared with an ascending aorta input, and together the two studies highlight dynamic long axial field of view FDG PET/CT as a tool for non-invasive quantification of kinetic parameters.

A second study pushed the same non-invasive logic into vascular medicine. Van Leeuwen and colleagues tested the feasibility of oxygen-15 labelled water PET/CT for quantifying lower limb muscle perfusion in patients with peripheral arterial occlusive disease. In this pilot study, scans from five patients demonstrated reproducible results. The kinetic analysis relied on an input function extracted from the superficial femoral artery, allowing non-invasive quantification of blood flow in most of the studied patients. The authors of the editorial caution, however, that the small diameter of that artery relative to the scanner’s resolution, combined with patient motion, may have affected the accuracy of the input function estimate and therefore the calculated kinetic parameters. Further studies are needed to determine the extent of those effects.

The third dynamic imaging study moved to the brain and to a more chemically complex tracer. Salvi de Souza and colleagues evaluated image-derived input functions for quantifying cerebral uptake of fluorine-18 MC225 on a long axial field of view scanner. Unlike FDG and water, MC225 is metabolised in the body, which complicates the extraction of an input function from image data alone and normally requires additional arterial blood samples. The study asked whether venous samples could replace the arterial ones. The answer, unfortunately, was no; the results were not promising. The editorial points out that this negative outcome may reflect an insufficient number of patients and external factors affecting the reliability of the blood measurements, leaving the question open rather than settled.

Quantitative results are only trustworthy if scanners behave consistently, which is the concern of the fourth study. Holman and colleagues assessed whether the Biograph Vision Quadra PET/CT complies with the accreditation programme of the European Association of Nuclear Medicine Research Ltd, known as EARL. The programme’s importance lies in enforcing consistency across different scanners and centres, a prerequisite for optimised clinical trials and longitudinal studies in which measurements from many sites must be comparable. The work considered both static and continuous bed motion acquisitions and concluded that both EARL1 and EARL2 criteria were met, mirroring the findings of a concurrent article by Roya and colleagues. Both articles highlighted the need for a new version of the EARL criteria designed specifically for modern long axial field of view PET/CT systems.

The fifth study addresses a very different bottleneck: the reports themselves. Bosbach and colleagues conducted a pilot study in melanoma patients scanned with total body PET/CT for restaging purposes, using a large language model to generate reports describing the patient’s status and any relevant changes compared with previous scans. The findings showed that in some cases the model-generated reports were slightly preferred over human reports. Given the rapid pace of development in this domain, the editorial suggests that the future use of large language models as a standard reporting tool would not be unexpected. The anticipated advantages include reducing the workload of medical doctors, lessening the dependence of report quality on individual experience, and freeing clinicians to spend more time on other activities and research.

The final study departs from clinical application altogether and explores a fundamentally new imaging contrast. Positronium is a short-lived entity formed by a positron-electron pair, and its lifetime depends on its quantum form and its surrounding environment. The decay time can be measured from the time difference between the detection of an emitted prompt gamma photon and the annihilation photon pairs of a decaying nucleus. In this first study the authors described how to produce quantitative measurements of positronium lifetime and illustrated lifetime images in a controlled experimental setup using phantoms.

Taken together, the six articles sketch a field that has emerged very recently but is advancing on several fronts simultaneously. The editorial observes that a bright future is expected for total body PET in both clinical practice and research, and notes that a second volume of the research topic has been launched to accommodate the growing number of submissions.

Subject of Research: Editorial overview of a research topic on total body positron emission tomography covering dynamic imaging, scanner accreditation, automated reporting and positronium lifetime imaging.

Article Title: Editorial: Total body positron emission tomography: science and clinical applications

Article References: Tsoumpas, C., Providência, L., Glaudemans, A. W. J. M., Slart, R. H. J. A., & Lammertsma, A. A. (2026). Editorial: Total body positron emission tomography: science and clinical applications. Frontiers in Nuclear Medicine, 6, Article 2028201. https://doi.org/10.3389/fnume.2026.2028201

Image Credits: AI Generated

DOI: 10.3389/fnume.2026.2028201

Keywords: total body PET, positron emission tomography, long axial field of view, image-derived input function, dynamic PET, FDG, peripheral arterial occlusive disease, EARL accreditation, large language models, positronium lifetime imaging, nuclear medicine, molecular imaging