Non-[18F]FDG PET-Radiopharmaceuticals in Oncology

Abstract

Molecular imaging is a growing field, driven by technological advances, such as the improvement of PET-CT scanners through the introduction of digital detectors and scanners with an extended field of view, resulting in much higher sensitivity and a variety of new specific radiopharmaceuticals that allow the visualization of specific molecular pathways and even theragnostic approaches. In oncology, the development of dedicated tracers is crucial for personalized therapeutic approaches. Novel peptides allow the visualization of many different targets, such as PD-1 and PD-L1 expression, chemokine expression, HER expression, T-cell imaging, microenvironmental imaging, such as FAP imaging, and many more. In this article, we review recent advances in the development of non-[¹⁸F]FDG PET radiopharmaceuticals and their current clinical applications in oncology, as well as some future aspects.

Keywords: PET radiopharmaceuticals; immuno-PET; oncology; total-body PET.

Figure 1

Maximum intensity projection (MIP) images of a patient with multiple myeloma 1 h after i.v. [¹⁸F]FDG injection (left side) and 1 h after [¹⁸F]FLT injection (right side). The [¹⁸F]FLT images show high uptake in the bone marrow of the axial skeleton, the pelvic bones, the spleen, and the liver. The [¹⁸F]FDG images show no focal or diffuse enhanced uptake in the bone marrow. Normal [¹⁸F]FDG excretion in the urinary tract.

Figure 2

Example of a patient with biochemical recurrence of prostate cancer. MIP images 1.5 h after i.v. injection of [¹⁸F]PSMA-1007 (left side) and 1.5 h after application of [⁶⁸Ga]Ga-PSMA-11 (right side) on the following day due to some non-specific bone uptake of [¹⁸F]PSMA-1007. Fused transversal images of a prostate cancer recurrence (red arrow) with both tracers. Of note is the different distribution of the two tracers. Enhanced hepatobiliary excretion of the [¹⁸F]PSMA-1007. Increased urinary excretion of [⁶⁸Ga]Ga-PSMA-11.

Figure 3

Pie chart showing the percentage of radionuclides used for labeling of different targets for PET immunoimaging.