Navigation Links
Scatter radiation from mammography presents no cancer risk

CHICAGO The radiation dose to areas of the body near the breast during mammography is negligible, or very low, and does not result in an increased risk of cancer, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA). The results suggest that the use of thyroid shields during mammography is unnecessary.

"Thyroid shields can impede good mammographic quality and, therefore, are not recommended during mammography," said Alison L. Chetlen, D.O., assistant professor of radiology at Penn State Hershey Medical Center.

During mammography, some X-rays scatter away from the primary beam in the breast and spread outward in different directions. Although this scatter radiation is much weaker than the primary beam, there has been concern that women exposed to it during mammography could face an increased risk of cancer, especially in radiosensitive areas like the thyroid gland.

To better understand the potential impact of scatter radiation, Dr. Chetlen and colleagues set out to measure the dose received by the thyroid gland, salivary gland, sternum, uterus and the lens of the eye during screening digital mammography. Each of the 207 women in the study group wore six optically stimulated luminescent dosimeters -- a device used to measure an absorbed dose of ionizing radiation -- while undergoing two-view screening mammography.

Analysis of the dosimeters by a medical physicist immediately after the exam revealed that the doses to the various areas outside of the breast ranged from negligible to very low.

Absorbed radiation dose is measured in a unit called a milligray (mGy). The average estimated organ dose to the salivary gland was 0.05 mGy. The average estimated organ dose to the thyroid gland was 0.05 mGy. These doses are only a fraction of the radiation people are exposed to from natural background sources, such as cosmic radiation and radionuclides in the ground. In fact, all areas except for the sternum received less than 2 percent of annual background radiation dose.

Measured dose to the bridge of the eye and umbilicus was negligible, indicating no increased risk to the patient of cataracts or interference with normal embryonic development in early pregnancy.

"The risk of cancer induction at these low levels is indistinguishable from background incidence of cancer due to other sources," Dr. Chetlen said.

The findings are particularly important in light of a recent increase in the incidence of thyroid cancer, one of the most radiosensitive of all cancers. The number of thyroid cancer diagnoses in women nearly doubled from 2000 to 2008, leading some to suspect that mammography may be a contributing factor and that women should wear lead thyroid shields during exams, an idea that Dr. Chetlen and other mammography experts strongly discourage.

Based on the extremely low scatter radiation dose to the thyroidequivalent to just a few minutes of background radiation, thyroid shields are unnecessary during mammography. In addition, the researchers warn that use of thyroid shields could result in an increased radiation dose to patients.

"A thyroid shield gets in the way of the exam and can actually cause an increase in radiation dose by necessitating repeat exams," Dr. Chetlen said.

Dr. Chetlen also pointed out that the thyroid gland is far less radiosensitive after age 30. The American Cancer Society and other organizations recommend that women have mammography screening once every year, beginning at age 40.

"In the age group eligible for screening, the thyroid gland is not very radiosensitive," Dr. Chetlen said.


Contact: Linda Brooks
Radiological Society of North America

Related medicine news :

1. Imaging facility develops successful radiation dose reduction program
2. Delaying radiation therapy after hysterectomy ups risk of uterine cancer recurrence
3. ASTRO: Deviating from radiation protocols increases risk of treatment failure and death
4. Radiation treatment after surgery improves survival for elderly women with early-stage breast cancer
5. Many Mistakenly Think Radiation Might Cure Terminal Lung Cancer
6. Study: No Long-Term Heart Risks From Breast Radiation
7. Mayo Clinic: Antidepressant eases radiation-related mouth pain in head, neck cancer
8. Minorities most likely to have aggressive tumors, less likely to get radiation
9. Fasting makes brain tumors more vulnerable to radiation therapy
10. Stage I NSCLC patients who receive radiation therapy are surviving longer
11. Brain radiation after lung cancer treatment reduces risk of cancer spreading
Post Your Comments:
(Date:11/27/2015)... VVA (PRWEB) , ... November 27, 2015 , ... ... motto of progress through sharing, the 2016 Building Better Radiology Marketing ... The conference will begin on Sunday, March 6, 2016, at Caesars Palace in ...
(Date:11/27/2015)... ... November 27, 2015 , ... CBD College is proud to ... Programs (CAAHEP) awarded accreditation to its Diagnostic Medical Sonography program. CBD College is honored ... one of twelve colleges and universities in the state of California make the cut. ...
(Date:11/26/2015)... ... November 26, 2015 , ... Patients at Serenity Point ... come together on Thanksgiving Day to share the things that they are most ... Serenity Point YouTube channel, patients displayed what they wrote on index cards, describing ...
(Date:11/26/2015)... ... , ... Jobs in hospital medical laboratories and in the imaging field lead ... Aureus Medical Group . These fields, as well as travel nursing, ... healthcare jobs through the company’s website, , The leading healthcare staffing ...
(Date:11/26/2015)... ... November 26, 2015 , ... Indosoft Inc., developer and distributor of the ... to improve system efficiency and reliability. , The new Q-Suite 6 platform is based ... system avoids locking itself into a specific piece of software for many key components ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... , Nov. 26, 2015 Research and ... the "Advanced Wound Care Market by Type (Dressings, ... End User (In-Patient Facility, Out-Patient Facility), and Geography - ... --> --> ... description, definition and forecast of the global advanced wound ...
(Date:11/26/2015)... ) has announced ... High Viscosity Drugs" report to their offering. ... addition of the "Self Administration of High ... --> Research and Markets ( ) ... Administration of High Viscosity Drugs" report to ...
(Date:11/26/2015)... , November 26, 2015 /PRNewswire/ ... announced the addition of the  "2016 ... the European Cell Surface Marker Testing ... Opportunities"  report to their offering.  ... the addition of the  "2016 Future ...
Breaking Medicine Technology: