Dose awareness isn’t just for CT
Though on average the median levels of radiation dose fell squarely in line with the levels recommended by the society, there was significant individual variation. On the bone scan side, one patient received 19 millicuries of radiation for another patient’s 36. And the radiation levels for PET scans ranged from 3 to 23 millicuries, though the suggested range is 10-20.
Fahey cautions that the data might be biased, since centers that seek accreditation might be more scrupulous in their dose administration than centers that don’t, but the study is still the largest review of its sort.
On the manufacturing end, CT dose reduction efforts have been met with measurably significant success, as there’s been a big market to satisfy increased demand for lower dose technologies. But whether this momentum will translate over to molecular imaging is questionable.
“It’ll be more of a challenge on the nuclear medicine side because we’ve been trying to administer the minimum dose all along. I don’t think we’ll see factor of 10 dose reduction — more like factor of two,” said Fahey.
Furthermore, data is really the key to understanding how to use dose correctly, but collecting it is a particular challenge for the molecular imaging industry.
This means that the dose data is recorded manually by the technologist into an online log, or sometimes even on paper or in a book, meaning that there’s much more difficulty sending that data over to the proper channels to be analyzed.
“In the ACR dose registry, nobody’s having to type or write anything,” said Fahey. “It’s easier to fix things when you know exactly what you’re doing.”
Finally, the society has developed a global initiative involving 12 other nuclear medicine societies around the world, including national organizations from Japan, Korea, China, Australia, South Africa, and Canada.
Its first project was pediatric dose optimization, which builds on the Image Gently campaign to raise awareness on dose optimization across different countries.
Due to its recent radiation scare in 2011, Japan, which has one of the largest imaging markets in the world, has seen a surge of focus on dose reduction, spurring practitioners in the country to proactively seek out and develop guidelines to keep dose at a reasonable level.
The SNNMI is also interested in working closely with societies in Europe to develop better dose guidelines and protocols.
“They came out with their pediatric dose statement in 2007 and we came out with ours in 2011. By 2014 they will be pretty much the same, which is a good thing,” said Fahey.