Machine improves breast exams

Molly Ball

Monday, Dec. 12, 2005 | 8:12 a.m.

Dr. Hales Keir studied the rounded shapes on the computer screen.

"These are fairly dense breasts," he said.

"In breasts which are dense like this, it can be harder to identify cancers because they look just like the dense breast material," explained Keir, a radiologist at the Nevada Cancer Institute.

On Keir's screen, he can make the breast tissue lighter or darker as he searches for the tiny masses that may mean breast cancer. He can turn it in every direction, zooming in on small areas and blowing them up to several times actual size. He can activate a computer program that adorns the screen with tiny color-coded arrows, stars and outlines, alerting him to areas the computer thinks he should take a look at.

The institute has just acquired a digital mammography machine, a piece of equipment that allows women to get mammograms with less time, anxiety and risk. It also improves the accuracy of cancer detection, possibly saving lives in the process. And it will allow the institute to participate in scientific studies, advancing its mission of research.

The difference between a regular analog mammography and digital mammography seems simple. A regular machine, like a film camera, takes X-ray pictures on film; a digital machine, like a digital camera, records the images in digital files.

But this seemingly technical distinction makes a big difference. In a study published in October in the New England Journal of Medicine, almost 50,000 women were given both analog and digital mammograms. In women younger than 50, women whose breast tissue is dense and women on the verge of menopause, the digital readings were about 27 percent more accurate.

"One of the most important ways to tell if something is cancerous is, are the edges of the lesion smooth or are they jagged?" said Dr. Dava Gerard, chief operating officer of the cancer institute, a breast surgeon who has testified before Congress about mammograms.

"If the lesion is very tiny, it can be hard to tell," she said. But with a digital image's high resolution and ease of manipulation, it's easy to magnify the image and look closely at its edges.

The cancer institute's digital mammography equipment is not the first in the Las Vegas Valley. That honor went to St. Rose Dominican Hospital-Siena, which opened with an all-digital radiology department in 2000.

"We love it, and our radiologists love it," St. Rose spokeswoman Mandy Abrams said. "Not only does it take less time, but it means less callbacks for patients."

About 20 percent of patients who get analog mammograms have to come back for a second shoot, either because something went wrong in the film processing or because the radiologist wants a closer look at a certain part of the breast. With digital exams, callbacks still happen, but much less frequently.

"Women hate to get mammograms," Abrams said. "If they hear that it's going to take less time, patients are very happy."

Southern Hills Hospital also began offering digital mammography when it opened last year. Another advantage of the technology is that it delivers less radiation, Mammographer Trish Alley said.

The technology is not cheap -- the cancer institute's new machine cost $450,000, versus less than $100,000 for an analog machine. But Alley said both she and her patients have become digital devotees.

"I'll never go back," she said. "I tell that to everyone."

Since the digital images are stored on CDs or in computer memory, rather than in messy drawers full of films, they are easier for patients to keep track of if they move or switch doctors, Alley noted. Comparing a new mammogram to an old one is the best way to detect cancer, so having old images on hand is potentially life-saving.

Gerard was quick to point out that women should still get mammograms even if only analog is available. Doctors recommend that women get mammograms every year or two past the age of 40, in addition to an annual clinical breast exam.

For the cancer institute, the mammogram machine means being able to participate in large-scale cancer studies such as the recently published one of 50,000 women, conducted at 33 sites across the United States and Canada.

"Fifty-thousand women entered a clinical trial to provide us with new information. That's the importance of clinical trials," Gerard said.

"Nevada Cancer Institute is here to really push that envelope of knowledge, while also providing technology to the community."

Molly Ball can be reached at 259-8814 or at molly@lasvegassun.com.