Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Cancer risk from medical radiation may have been overestimated

The risk of developing radiation-induced cancer from computed tomography (CT) may be lower than previously thought, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

"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 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. (

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

Linda Brooks | EurekAlert!
Further information:

Further reports about: CT scans Cancer Medicare RSNA ionizing radiation radiation dose radiation exposure

More articles from Health and Medicine:

nachricht Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>