A simple and efficient method to recover isotopically enriched Ni-64 from electrolytic solutions.

Production of 64Cu via the proton irradiation of 64Ni, electrodeposited on a suitable backing substrate, remains the most common method to produce this emerging radionuclide. Some unforeseen cases arise when the electrodeposition does not work and the electrolytic solution needs to be reprocessed, but the presence of salt buffers makes it difficult to recover the nickel to prepare a fresh solution. The aim of this work was to develop a simple and efficient method to recover 64Ni from bath solutions.

Biodistribution and radiation dosimetry of [64Cu]copper dichloride: first-in-human study in healthy volunteers.

BACKGROUND: In recent years, Copper-64 (T1/2 = 12.7 h) in the chemical form of copper dichloride ([64Cu]CuCl2) has been identified as a potential agent for PET imaging and radionuclide therapy targeting the human copper transporter 1, which is overexpressed in a variety of cancer cells. Limited human biodistribution and radiation dosimetry data is available for this tracer. The aim of this research was to determine the biodistribution and estimate the radiation dosimetry of [64Cu]CuCl2, using whole-body (WB) PET scans in healthy volunteers. Six healthy volunteers were included in this study (3 women and 3 men, mean age ± SD, 54.3 ± 8.6 years; mean weight ± SD, 77.2 ± 12.4 kg). After intravenous injection of the tracer (4.0 MBq/kg), three consecutive WB emission scans were acquired at 5, 30, and 60 min after injection. Additional scans were acquired at 5, 9, and 24 h post-injection. Low-dose CT scan without contrast was used for anatomic localization and attenuation correction. OLINDA/EXM software was used to calculate human radiation doses using the reference adult model. RESULTS: The highest uptake was in the liver, followed by lower and upper large intestine walls, and pancreas, in descending order. Urinary excretion was negligible. The critical organ was liver with a mean absorbed dose of 310 ± 67 µGy/MBq for men and 421 ± 56 µGy/MBq for women, while the mean WB effective doses were 51.2 ± 3.0 and 61.8 ± 5.2 µSv/MBq for men and women, respectively. CONCLUSIONS: To the best of our knowledge, this is the first report on biodistribution and radiation dosimetry of [64Cu]CuCl2 in healthy volunteers. Measured absorbed doses and effective doses are higher than previously reported doses estimated with biodistribution data from patients with prostate cancer, a difference that could be explained not just due to altered biodistribution in cancer patients compared to healthy volunteers but most likely due to the differences in the analysis technique and assumptions in the dose calculation.