⁶⁴Cu²⁺ Ions as PET Probe: An Emerging Paradigm in Molecular Imaging of Cancer

Positron emission tomography (PET) imaging has transformed diagnostic nuclear medicine and become an essential strategy in cancer management. With the expected growth of this molecular imaging modality, there is a recognized need for new PET probes to address the clinical challenges in the early diagnosis and staging of various types of cancers. In this endeavor, the prospect of using ⁶⁴Cu in the form of simple Cu²⁺ ions as PET probe is not only a cost-effective proposition but also seems poised to broaden the palette of molecular imaging probes in the foreseeable future. The usefulness of ⁶⁴Cu²⁺ ions as PET probe is based on the fact that Cu is an essential element that plays an important role in cell proliferation and angiogenesis. Over the past few years, there has been continuous flow of evidences based on studies in animal models on the uptake of ⁶⁴Cu²⁺ ions in different types of tumors, including, hepatoma, colorectal cancer, prostate cancer, lung cancer, breast cancer, head and neck cancer, fibrosarcoma, melanoma, glioblastoma, and ovarian cancer. The widespread preclinical success of ⁶⁴Cu²⁺ ions as PET probe has recently resulted in translation of this radiotracer to clinical settings for noninvasive imaging and staging of prostate cancer in human patients. In this concise review, we have focused on the latest developments in PET imaging of cancer in preclinical and clinical settings using ⁶⁴Cu²⁺ ion as a probe and discussed the challenges and opportunities for future development.