Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New nuclear breast imaging technologies associated with higher cancer risks

24.08.2010
Some nuclear-based breast imaging exams may increase a woman's risk of developing radiation-induced cancer, according to a special report appearing online and in the October issue of Radiology. However, the radiation dose and risk from mammography are very low.

"A single breast-specific gamma imaging (BSGI) or positron emission mammography (PEM) examination carries a lifetime risk of inducing fatal cancer greater than or comparable to a lifetime of annual screening mammography starting at age 40," said the study's author, R. Edward Hendrick, Ph.D., clinical professor of radiology at the University of Colorado-Denver, School of Medicine in Aurora, Co.

The risks and benefits of screening mammography are under constant scrutiny. Meanwhile, newer breast imaging technologies, such as BSGI and PEM have been approved by the U.S. Food and Drug Administration (FDA) and introduced into clinical practice. Preliminary studies have shown both to be promising at detecting cancer; however, both involve the injection of radioactive material into the patient.

BSGI uses a high-resolution gamma camera that allows for imaging with mild compression of the breast along with an injection of a nuclear radiotracer, which is absorbed at a higher rate by cancerous cells. In PEM, radioactive material is injected into the body to measure metabolic activity and determine the presence of disease. Other technologies, not yet approved by the FDA, include dedicated breast CT and digital breast tomosynthesis.

Dr. Hendrick reviewed recent studies on radiation doses from radiologic procedures and organ doses from nuclear medicine procedures, along with Biologic Effects of Ionizing Radiation (BEIR) VII age-dependent risk data, to estimate the lifetime risk of radiation-induced cancer incidence and death from breast imaging exams using ionizing radiation.

Two-view digital mammography and screen-film mammography were found to have an average lifetime risk of fatal breast cancer of 1.3 and 1.7 cases, respectively, per 100,000 women aged 40 years at exposure and less than one case per one million women aged 80 years at exposure. Annual screening mammography (digital or screen-film) performed in women from age 40 to age 80 is associated with a lifetime risk of fatal breast cancer of 20 to 25 cases in 100,000.

"Two-thirds of mammography units in the U.S. are now digital, which, on average, exposes the patient to an even lower radiation dose than screen-film," Dr. Hendrick said. "Manufacturers and breast centers continue to take steps to lower radiation doses on digital mammography systems without negatively affecting image quality."

Dedicated breast CT and digital tomosynthesis were both found to have an average lifetime risk of fatal breast cancer of 1.3 to 2.6 cases, respectively, per 100,000 women 40 years of age at exposure.

A single BSGI exam was estimated to involve a lifetime risk of fatal cancer 20 to 30 times that of digital mammography in women aged 40 years, while the lifetime risk of a single PEM was 23 times greater than that of digital mammography. In addition, while mammography only slightly increases a woman's risk for breast cancer, BSGI and PEM may increase the risk of cancers in other organs as well, including the intestines, kidneys, bladder, gallbladder, uterus, ovaries and colon.

People are exposed to radiation from natural sources all the time. The average person in the U.S. receives an effective dose of about 3 millisieverts (mSv) per year from naturally occurring radioactive materials and cosmic radiation from outer space. The average effective dose from two-view screen-film (0.56 mSv) or digital mammography (0.44 mSv) is equivalent to approximately two months of natural background radiation, while the effective doses from BSGI (6.2 mSv) and PEM (9.4 mSv) exams equal approximately two to three years of natural background radiation exposure.

Currently, no one is advocating using PEM or BSGI as a screening method to replace mammography. These exams are typically performed on women with suspicious breast lesions and in women with dense breasts who are difficult to examine with other techniques. Despite the increased radiation dose, these exams have shown promise in detecting cancer accurately and may have a good risk-benefit ratio for some specific indications.

"The primary tool for breast cancer screening is still mammography, which has a very low radiation dose and a very low lifetime risk of cancer induction," Dr. Hendrick said. "The risk of missing a breast cancer because mammography is not done far outweighs the tiny risk of mammography causing a breast cancer."

He added that the subset of women under 40 who are known to be at higher risk of breast cancer should consider being screened with breast ultrasound or breast MRI, both of which deliver no ionizing radiation and have sensitivities to breast cancer that are unaffected by higher breast density.

"Radiation Doses and Cancer Risks from Breast Imaging Studies." Disclosures: Dr. Hendrick is a consultant to GE Healthcare regarding digital breast tomosynthesis and a member of the medical advisory boards of Koning (dedicated breast CT) and Bracco (MR contrast agents). No support from any industry source was provided for this study, and the study results have not been shared with or in any way influenced by commercial entities.

Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc. (http://radiology.rsna.org/)

RSNA is an association of more than 44,000 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)

For patient-friendly information on breast imaging, visit RadiologyInfo.org.

Linda Brooks | EurekAlert!
Further information:
http://www.rsna.org

More articles from Medical Engineering:

nachricht Novel breast tomosynthesis technique reduces screening recall rate
21.02.2017 | Radiological Society of North America

nachricht Biocompatible 3-D tracking system has potential to improve robot-assisted surgery
17.02.2017 | Children's National Health System

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Viruses support photosynthesis in bacteria – an evolutionary advantage?

23.02.2017 | Life Sciences

Researchers pave the way for ionotronic nanodevices

23.02.2017 | Power and Electrical Engineering

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>