Resolving of Transportation Issue With High Activity Positron Emission Tomography Radiotracer Source to Long Distance Medical Imaging Centers

In Indian scenario, single positron emission tomography (PET) radiotracer isotope production center is catering PET radiopharmaceuticals to multiple medical imaging centers, located far away from the production center. Road, rail, and air are the modes of transport that are being used to deliver PET source depending on the transportation time required for the receiving center. The longer transportation time leads to the reduction of source activity due to its own radioactive decay process. At present, carrier pot made of lead (LP-30) is utilized for transportation of activity of around 300 mCi. However, due to long distance of imaging centers from PET production center, transportation pots of ¹⁸F-FDG (T_1/2= 109.8 min) source need to handle higher source strength in the order of 1500 mCi. To qualify the regulatory compliance and handling aspects during transportation, existing lead pot is found to be not suitable for transportation of high activity. Therefore, alternate design options have been explored that included an innovative design of container pot made of tungsten and tungsten-based alloy. Theoretical estimation of dose rate profile has been done using point kernel-based radiation shielding code IGSHIELD. Limited experimental verification of the theoretical predictions has also been done. It is found that containers made of tungsten alloy are appropriate for handling high activity ¹⁸F-FDG PET radiopharmaceuticals while transporting to imaging facilities that are far away.