Current and future perspectives on functional molecular imaging in nephro-urology: theranostics on the horizon.

In recent years, a paradigm shift from single-photon-emitting radionuclide radiotracers toward positron-emission tomography (PET) radiotracers has occurred in nuclear oncology. Although PET-based molecular imaging of the kidneys is still in its infancy, such a trend has emerged in the field of functional renal radionuclide imaging. Potentially allowing for precise and thorough evaluation of renal radiotracer urodynamics, PET radionuclide imaging has numerous advantages including precise anatomical co-registration with CT images and dynamic three-dimensional imaging capability. In addition, relative to scintigraphic approaches, PET can allow for significantly reduced scan time enabling high-throughput in a busy PET practice and further reduces radiation exposure, which may have a clinical impact in pediatric populations. In recent years, multiple renal PET radiotracers labeled with 11C, 68Ga, and 18F have been utilized in clinical studies. Beyond providing a precise non-invasive read-out of renal function, such radiotracers may also be used to assess renal inflammation. This manuscript will provide an overview of renal molecular PET imaging and will highlight the transformation of conventional scintigraphy of the kidneys toward novel, high-resolution PET imaging for assessing renal function. In addition, future applications will be introduced, e.g. by transferring the concept of molecular image-guided diagnostics and therapy (theranostics) to the field of nephrology.

Theranostics. 2021 Apr 07*** epublish ***

Yoshitaka Toyama, Rudolf A Werner, Camilo A Ruiz-Bedoya, Alvaro A Ordonez, Kei Takase, Constantin Lapa, Sanjay K Jain, Martin G Pomper, Steven P Rowe, Takahiro Higuchi

Department of Nuclear Medicine, University Hospital Wuerzburg, Wuerzburg, Germany., Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland., Department of Diagnostic Radiology, Tohoku University, Sendai, Japan., Nuclear Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany., Division of Nuclear Medicine and Molecular Imaging, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.