New PET/CT Contrast Agent Uses Copper as a Prostate Cancer Imaging Biomarker
Researchers test the ability of copper-64 chloride PET/CT to detect prostate cancer lesions in patients after relapse
Previous research has indicated that tumors have an increased concentration of copper due to the element's role in regulating cell proliferation, which has brought up the possibility of copper as a possible cancer imaging biomarker. In particular, a novel PET/CT agent called copper-64 chloride has been tested in mouse models and a limited number of human patients with prostate cancer. In these studies, the tumor displays an increased uptake of copper administered as copper-64 chloride when compared to normal tissue.
In a new study, researchers from Galliera Hospital in Italy investigated the ability of copper-64 chloride PET/CT to detect prostate cancer recurrence in patients after surgery or radiation therapy. To evaluate its performance, they compared the results with those from two more established imaging techniques for prostate cancer, fluorine-18-choline PET/CT and multiparametric MRI. Their findings were published by the Journal of Nuclear Medicine Sept. 8.
From February to October 2016, the authors scanned 50 patients with prostate cancer, all of whom showed a rise in the blood level of prostate-specific antigen which indicates biochemical recurrence. Whole body PET/CT was performed on two separate days -- one scan took place an hour after injection of copper-64 chloride, while the other happened 20 minutes after injection of fluorine-18-choline.
No adverse reactions occurred after the injection of copper-64 chloride. The agent's distribution throughout the body also appeared more suitable for evaluating prostate cancer relapse than fluorine-18-choline, since it wasn't excreted or accumulated in the urinary tract. The copper-64 chloride PET/CT images allowed for better assessment of the pelvis and prostatic fossa, the cavity where the prostate gland lies.
Lastly, the researchers performed a lesion-based analysis to determine the detection rate of each modality in identifying recurrent lesions in different anatomic locations. Copper-64 chloride PET/CT detected 103 out of 118 lesions (87 percent), while multiparametric MRI identified 84 lesions (71 percent) and fluorine-18-choline PET/CT identified 69 (59 percent). Despite its good performance, larger clinical trials will be needed in the future to further investigate the contrast agent's efficacy in prostate cancer management.