Nuclear Imaging Probes: from Bench to Bedside

Abstract

The availability of specific imaging probes is the nuclear fuel for molecular imaging by positron emission tomography and single-photon emission computed tomography. These two radiotracer-based imaging modalities represent the prototype methods for noninvasive depiction and quantification of biochemical processes, allowing a functional characterization of tumor biology. A variety of powerful radiolabeled probesötracersöare already established in the routine clinical management of human disease and others are currently subject to clinical assessment. Emerging from investigations of the genomic and proteomic signatures of cancer cells, an increasing number of promising targets are being identified, including receptors, enzymes, transporters, and antigens. Corresponding probes for these newly identified targets need to be developed and transferred into the clinical setting. Starting with a brief summary of the characteristics and prerequisites for a ''good tracer,'' an overview of tracer concepts, target selection, and development strategies is given. The influence of the imaging concepts on tracer development is also discussed.

In vivo imaging of Aminopeptidase N (CD13) receptors in experimental renal tumors using the novel radiotracer 68Ga-NOTA-c(NGR)

“…Among in vivo, functional imaging techniques, Positron Emission Tomography is one of the most sophisticated methods that also makes it possible to detect tumors with high accuracy and sensitivity followed by easy quantification (Wester 2007 Ga-generators and offers a well-established complexation chemistry for the labeling of biomolecules (Velikyan 2013;Smith et al, 2013;Banerjee and Pomper 2013). To our knowledge, only a few 68 Ga-labeled NGR conjugates were evaluated under preclinical circumstances for CD13-expression-imaging (Zhang et al, 2014;Shao et al, 2014b).…”

Noninvasive optical imaging of nitroreductase gene-directed enzyme prodrug therapy system in living animals

“…19 Several radiotracers, including, 11 Carbon 18 Fluorine, 124 Iodine, 64 Copper and 68 Gallium, are used to label enzyme substrates for PET imaging, whereas 123 Iodine, 131 Iodine, 111 Indium and 99 Technetium are used for SPECT imaging. 20 However, currently there are very few therapeutic reporters for suicide gene therapy that contain a direct imageable probe and whose resultant image from probe-enzyme interaction brings information about probe localization or tracks expression of the transgene in vivo.…”

New developments in imaging and functional biomarker technology for the assessment and management of cancer patients

“…Molecular imaging, as it relates to oncology, encompasses a diverse spectrum of both imaging modalities and targeted tracers [1][2][3][4][5][6][7]. The impact of molecular imaging on oncology extends from guiding preclinical development of targeted biomarkers and therapeutic agents, to assisting in the diagnosis and staging of malignant diseases, as well as the monitoring of therapeutic response.…”

“…The impact of molecular imaging on oncology extends from guiding preclinical development of targeted biomarkers and therapeutic agents, to assisting in the diagnosis and staging of malignant diseases, as well as the monitoring of therapeutic response. To date, the use of imaging with and without targeted biomarkers to assess functional measures of disease has yielded promising results [5]. These early results have sparked a broadened interest and rapid growth in molecular imaging technology and the further development of targeted biomarkers [6,7].…”

“…The future of targeted imaging biomarkers and functional measures in the assessment and management of cancer patients is very promising [1][2][3][4][5][6][7]. The rapid growth and development of functional imaging technology, both preclinically and clinically, combined with the development of a wide variety of targeted diagnostic and therapeutic biomarkers, is revolutionizing the development of conventional therapeutic agents and changing how we approach the care and management of cancer patients.…”