Positron Emission Tomography Using 64-Copper as a Tracer for the Study of Copper-Related Disorders

This method has already proven to be significant in the study of Wilson disease because we can visualize copper distribution in patients. The benefit of copper PET imaging lies in the ability to monitor its bio distribution within the body, facilitating non-invasive visualization and quantification of the copper concentration in various organs. This technique can be used in the diagnosis of Wilson disease and in research settings for testing treatment effects.

In the future, the technique may also be used in clinical settings for treatment effect monitoring, and perhaps in other diseases with disturbed copper metabolism. To begin, wear plastic gloves. Using long tweezers, thoroughly disinfect the rubber membrane of the tracer containing glass bottle inside the lead container with a disinfection swab.

Insert a short canula into the membrane using tweezers to prevent spillover from the vacuum inside the bottle. With tweezers, insert a longer canula into the membrane to draw the tracer solution. Insert an appropriately-sized plastic syringe into the long canula and draw the calculated volume of the tracer.

Using tweezers, attach a canula with a cap to close the syringe and carefully transfer the syringe to the dose calibrator to measure the radioactivity. Store it in a lead container until use. Measure the radioactivity in the syringe using the dose calibrator.

Note the time and activity on the worksheet. Wearing plastic gloves, carefully remove the cap and canula from the syringe using sterile tweezers. Connect the syringe to the patient's IV access.

Note the time on the worksheet. And inject the tracer in one steady movement. After injection, remove the syringe from the IV access.

Replace the cap and canula on the syringe and keep it that way till the remaining radioactivity is measured. Flush the IV access with saline solution to clear any remaining tracer. Note the time again.

Then measure the remaining radioactivity present in the syringe and note it on the worksheet. For oral administration, which is another way of administering the tracer, pour 100 milliliters of cordial into a disposable soft plastic cup. Using tweezers, remove the cap and canula from the syringe.

Then while wearing plastic gloves, carefully inject the tracer into the cup without spilling. Draw up a small amount of the cordial into the syringe and inject it back into the cup to ensure proper mixing. Place a plastic straw in the cup and hand over the cup to the participant.

Note the time on the worksheet. And allow the participant to drink the mixture. Place the empty cup, straw, and syringe into a disposable plastic bag and place them in the lead container if possible.

Note the time and measure the leftover radioactivity in the disposable bag with the syringe, plastic cup, and straw. Place the participant in a supine position in the scanner. Adjust the position of the scanner before beginning the scan.

Conduct an overview, CT, or MR scan to plan the specific region to be examined during the PET scan. In the PET scan protocol, note the time of the draw, injection, leftover measurement, and radioactivity levels at the draw and leftover measurement. Download the scan data as DICOM files and transfer them to an analysis program, like PMOD.

Adjust the tone settings of scans to differentiate the anatomical structures. Working in the horizontal plane, localize the liver and the big structures. Place appropriate volume of interest or multiple VOIs in the right lobe of the liver at different horizontal planes to obtain the most accurate standard uptake value measurements, considering that the value may vary by 5%within the right liver lobe.

Calculate the mean standard uptake value of these VOIs. In a study, comparing healthy subjects and patients with Wilson disease, the distribution of copper was monitored at six and 20 hours post-injection. In patients, copper was accumulating in the liver.

Whereas in healthy subjects, the copper is visible in gut segments with higher signals, indicating biliary copper excretion. 64 Copper scans were conducted utilizing an orally-administered tracer in two separate individuals with Wilson disease with and without zinc treatment. Zinc treatment effectively reduces copper absorption in the intestinal tract and subsequently lowers copper accumulation in the liver.

In a healthy individual, four weeks of zinc treatment reduced copper content in the liver to around 50%of the pre-treatment content in the group. Remember to look for big structures in the liver when placing the VOIs. And remember to adjust the VOI size to the organ size to avoid spillover from other organs.

The procedure can be cobbled with arterial blood sampling in order to perform kinetic analysis. And in addition to blood, copper-64 activity may also be measured in urine and feces.