"Radiation from medical imaging has gotten a tremendous amount of attention in recent years," said Aabed Meer, an M.D. candidate at Stanford University in Palo Alto, Calif. "This is one of the first studies to track CT utilization in such a large population."
The researchers conducted a retrospective study using Medicare claims from 1998 through 2005 to analyze the distribution of CT scans, determine the ionizing radiation exposure associated with the exams and estimate the associated cancer risk in a population of older adults.
"The study focused on the elderly Medicare population, which receives the highest amount of per capita radiation," Meer said. "We analyzed more than 10 million records from the Medicare claims database."
The data were studied in two groups, including 5,267,230 records from 1998 through 2001 and 5,555,345 records from 2002 through 2005. For each group, the researchers analyzed the number and types of CT scans that each patient received to determine the percentage of patients exposed to "low" radiation doses of 50 millisieverts (mSv) to 100mSv and "high" radiation doses, in excess of 100mSv. They then used standard cancer risk models to estimate the number of cancers induced.
CT scans of the head were the most common examinations, representing 25 percent of the first group and 30 percent of the second group. However, abdominal CT delivered the greatest proportion of radiation, accounting for approximately 40 percent of the total radiation exposure in each group. Imaging of the pelvis and chest represented the second and third largest sources of radiation.
From 1998 to 2001, 42 percent of patients underwent CT scans. From 2002 to 2005, 49 percent of patients underwent CT scans. The percentage of patients exposed to radiation doses in both the low and high ranges approximately doubled from the first group to the second group. The researchers found this to be consistent with the increasing use of high-speed CT in patient diagnosis and management.
Cancer incidences related to ionizing radiation from CT were estimated to be 0.02 percent and 0.04 percent of the two groups, respectively.
"Our findings indicate a significantly lower risk of developing cancer from CT than previous estimates of 1.5 percent to 2.0 percent of the population," said coauthor Scott Atlas, M.D., chief of neuroradiology at the Stanford University Medical Center. "Regardless, the increasing reliance on CT scans underscores the importance of monitoring CT utilization and its consequences."
Other coauthors are Laurence Baker, Ph.D., and Pat A. Basu, M.D.
Note: Copies of RSNA 2010 news releases and electronic images will be available online at RSNA.org/press10 beginning Monday, Nov. 29.
RSNA is an association of more than 46,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
Editor's note: The data in these releases may differ from those in the published abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.
For patient-friendly information on radiation safety, visit RadiologyInfo.org
Linda Brooks | EurekAlert!
How cancer metastasis happens: Researchers reveal a key mechanism
19.01.2018 | Weill Cornell Medicine
Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy