Prostate-Specific Membrane Antigen Ligands for Imaging and Therapy

The prostate-specific membrane antigen (PSMA) is highly expressed on most prostate cancer (PC) cells. Therefore, the targeting of PSMA has become increasingly important over the last decade. Glu-urea-based PSMA ligands used for both imaging and radioligand therapy are the mainstays of the current success. For PET imaging, both (68)Ga- and (18)F-labeled agents have been successfully translated to clinical applications. Mainly retrospective cohort studies have shown a high value in the setting of biochemical recurrence, with high detection rates even in the presence of low prostate-specific antigen levels. Preliminary data indicated that radioguided surgery with PSMA ligands may help to further improve patient outcomes because it facilitates the removal of small tumor deposits that are otherwise difficult to detect. For primary PC, PSMA ligand PET imaging has been shown to be superior to cross-sectional imaging for the detection of metastatic lymph nodes. In addition, it promises to also provide intraprostatic tumor localization, especially when used in combination with multiparametric MRI. Increasing numbers of studies have reported considerable changes in management resulting from PSMA ligand PET imaging for both biochemical recurrence and primary disease. The use of (177)Lu-PSMA-based radioligand therapy has demonstrated a reasonable response, mainly as defined by a prostate-specific antigen response of more than 50%, comparable to other recently introduced agents. Especially given the high level of safety of (177)Lu-PSMA radioligand therapy, with only minimal grade 3 and 4 toxicities reported so far, it has the potential to expand options for metastatic castration-resistant PC. This review is intended to provide a comprehensive overview of the current literature on low-molecular-weight PSMA ligands for both PET imaging and therapeutic approaches, with a focus on agents that have been clinically adopted.

Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2017 Sep [Epub]

Matthias Eiber, Wolfgang P Fendler, Steven P Rowe, Jeremie Calais, Michael S Hofman, Tobias Maurer, Sarah M Schwarzenboeck, Clemens Kratowchil, Ken Herrmann, Frederik L Giesel

Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California ., Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California., Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, Maryland., Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia., Department of Urology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany., Department of Nuclear Medicine, Rostock University Medical Centre, Rostock, Germany., Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany; and., Klinik für Nuklearmedizin, Universitätsklinikum Essen, Essen, Germany.