Italian researchers found an innovative nuclear medicine imaging agent that targets copper buildup in tumors to detect prostate cancer recurrence in patients with biochemical relapse.

Corresponding author Arnoldo Piccardo, with the department of nuclear medicine with E.O. Ospedali Galliera in Genoa, Italy, and colleagues pointed to separate studies that reported increased copper levels in tumors.

Researchers suggested the findings could pave a way for using elevated copper concentration in cancer cells as an imaging biomarker for metabolic PET imaging, according to Piccardo et al. in the study published in March’s Journal of Nuclear Medicine.

In the 50-patient study, researchers performed PET/CT scans using copper-64 chloride (⁶⁴CuCl₂), the new imaging agent, against fluorine-18-choline (¹⁸F-Choline).

"This is the first time this novel agent has been compared with ¹⁸F-Choline-PET/CT in a considerable number of prostate cancer patients with biochemical relapse," said Piccardo in a Society of Nuclear Medicine and Molecular Imaging release. "Early detection of prostate cancer relapse may improve the clinical management of patients, for example implementing early salvage radiotherapy."

Similar to established PET tracers, the most effective dose of the new imaging agent was 5.7 mSV. ⁶⁴CuCl₂ is not accumulated in, nor excreted from the urinary tract allowing for thorough pelvic assessment and an increased possibility of detecting small lesions near the bladder.

No adverse reactions were observed after the injection of ⁶⁴CuCl₂, and results show that ⁶⁴CuCl₂-PET/CT has a higher detection rate than ¹⁸F-Choline-PET/CT in patients with low levels of PSA (<1 ng/ml).

“This study determined that the biodistribution of ⁶⁴CuCl₂ is more suitable than that of ¹⁸F-choline for exploring the pelvis and prostatic bed,” wrote Piccardo et al. “In patients with biochemical relapse and a low PSA level, ⁶⁴CuCl₂-PET/CT shows a significantly higher detection rate than ¹⁸F-choline-PET/CT.”