March 21, 2002
Proper patient positioning may improve breast cancer detection
Seattle—What can women do to improve the effectiveness of their mammograms? A new study from Group Health Cooperative suggests that cooperating with the technologist to get in the right position may make a significant difference.
The study—the first of its kind—will be published in the April 2002 issue of the American Journal of Roentgenology, a major medical journal for radiologists. Researchers found that the chances of missing a cancer during mammography are more than twice as high when poor positioning occurs. Proper positioning allows visualization of the muscle behind the breast, the entire breast, and the nipple.
Moreover, Group Health found that a woman's position during the screening may have more impact in detecting breast cancer than other measures of image quality, such as breast compression, radiation exposure, and even the sharpness and contrast of the mammography film.
"Proper positioning depends on cooperation between the technologist and the patient during the screening," explained Stephen Taplin, MD, senior investigator for the Center Health Studies at Group Health Cooperative and the principal investigator of the study. "When the technologist asks a woman to lean in so more of her breast can be seen on the film, it really does make a difference," said Taplin.
Breast positioning has improved since the study data was collected (1988–1993), according to Edward Sickles, MD, professor of radiology at the University of California San Francisco School of Medicine. "We have learned more effective positioning maneuvers, and these have been widely taught over the past several years," Sickles said. In fact, federal guidelines passed in the mid-1990s now call for more education about breast positioning.
"Still, the field has never developed specific criteria that measure whether positioning is being done correctly," said Taplin. "This study came up with such criteria and then determined how many missed cancers were associated with mammograms where the criteria were not met. This had not been done before."
Taplin emphasized that the study shows only a correlation between positioning and cancers missed. There's no evidence of a direct cause and effect. Still, he believes that more training for technologists may improve outcomes.
"One implication of this study is that people in health care need to consider how well they are using the technology and what they can do to improve it," he added. "We won't get the outcomes we want unless we optimize the technology."
The Group Health study should encourage further research into the link between breast positioning and clinical outcomes, according to Stephen A. Feig, MD, of Mount Sinai School of Medicine's Department of Radiology. In a commentary that accompanies the article, Feig wrote that the study should also "encourage efforts to further ensure proper image quality in (radiology) practices and around our nation."
How the study was conducted
The study included 152 women who were diagnosed with breast cancer
within two years after a negative mammogram. When the women's mammogram
films were reviewed and scored according to a measurement tool developed
for the study, the researchers found that women with missed cancers were
more than twice as likely to have mammograms that did not meet the new
positioning
criteria. Problems with other quality measures—such as breast compression, radiation exposure, and image contrast—were rare.
The study is part of a large breast-cancer screening research program at Group Health, which is funded by a five-year, $4.3 million grant from the National Cancer Institute. The study was conducted by scientists from Group Health Center for Health Studies, the FDA, the University of Washington's Department of Family Medicine, and the Fred Hutchinson Cancer Research Center.
Group Health Center for Health Studies
Founded in 1947, Group Health Cooperative is a Seattle-based, consumer-governed, nonprofit health care system. The Group Health Center for Health Studies is Group Health’s research institute. For 25 years, the Center has conducted nonproprietary public-interest research on preventing, diagnosing, and treating major health problems. Government and private research grants provide its main funding.