October 5, 2006
Can MRI save lives?
High-tech scans help track down breast cancer in younger at-risk women when mammograms alone fail
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"This is not a pleasure to have," said Vinstein of Tower Saint John's Imaging. "This is a big test."
Patients must lie perfectly still for 15 minutes at a time, with breaks in between, over a period of 30 to 60 minutes. After the first scan, a patient is typically injected with gadolinium, a nonradioactive element that has a strong reaction to the frequencies generated by the machine.
Once a tumor has taken root in the breast, it sets up its own blood supply network. Gadolinium travels through the blood and gathers in abnormal tissue, which contains hydrogen atoms that differ from the same variety in healthy tissue. The MRI looks at the hydrogen in the body, and the gadolinium lights up these diseased areas.
Since the MRI only focuses on how hydrogen atoms react to the magnetic fields, Vinstein said, breast density isn't an issue.
Once the scan is complete, a computer compiles the data into a 3D image. "The computer can detect changes in the pixel color map and make things easier to see," he said.
Diagnostic workstations can now read results in as little as five to 15 minutes. Once the image is complete, it's possible to measure the exact size of the tumor.
In addition to screening for breast cancer, MRI technology has enabled surgeons to map specific tumor locations and perform more accurate biopsies. It has also helped oncologists monitor the effects of chemotherapy based on changes in tumor size.
What the technology is missing at this point is an assessment of whether its use as a screening tool improves survival odds.
"The problem is that there isn't the study to show that by finding the breast cancer early via MRI that the women remain breast cancer-free over a lifetime," he said. "Studies have shown that with mammography women live longer if it's found earlier."
Doctors like Jeffrey Weitzel, director of the Department of Clinical Cancer Genetics and the Cancer Screening and Prevention Program at the City of Hope Comprehensive Cancer Center in Duarte, say there's no point in waiting for mortality studies to prove the effectiveness of MRI.
"We don't need more data to recommend this," he said.
However, Weitzel believes women who don't fall into the high-risk categories do not need MRI and can stick with film or digital mammography. One big reason is cost.
Whereas mammograms might cost $100, an MRI can run $1,000 or more.
Dr. Philomena McAndrew of Tower Hematology Oncology Medical Group in Beverly Hills has been a big supporter of MRI for many years, especially for Ashkenazi women whose grandmothers, mother, aunts or siblings have been diagnosed with cancer. But she reluctantly agrees with Weitzel on cost-effectiveness for low-risk women.
"Unfortunately because of the cost it's clearly for the higher risk groups - inherited mutations such as BRCA 1 and 2 and a prior breast cancer that wasn't picked up a mammogram or ultrasound," said McAndrew, who will be the featured speaker at an Israel Cancer Research Fund event on Oct. 11.
While MRI might carry sticker shock for some, a Stanford study published in the May 24 issue of the Journal of the American Medical Association concluded that use of the technology to screen BRCA 1 carriers under the age of 50 was more cost-effective than simply relying on mammography alone. For BRCA 2 carriers, no such cost-efficiency was found.
Yet in spite of such high accolades, MRI falls short in a key area of breast cancer screening: detecting calcifications.
Calcium deposits in breast tissue are common, and many women will have a least one calcification show up on a mammogram as a bright white fleck. Many are non-cancerous, but calcifications with irregular shapes that form in tight clusters can be an early indication of breast cancer.
But MRI cannot show these calcifications.
Vinstein of Tower Saint John's Imaging said that while revolutionary, MRIs are intended to compliment rather than replace the mammogram. He believes the widely used X-ray technique still plays a critical role in cancer screening.
"Unless a patient has had a mammogram in the last six month, we'll have her repeat one and get an ultrasound," he said.
Leslie Berlin credits the MRI with helping to save her life.
A biopsy found her cancer was fueled by estrogen, and was too aggressive to consider lumpectomy. After consulting with her oncologist, she decided to have a double mastectomy to avoid future problems.
"I didn't want to go through this again, and it probably would have happened again," she said.
On April 23, 2003, Berlin underwent surgery at Cedars-Sinai, the same hospital where she and her twin sister had been born more than two months premature. "They saved my life twice," she said.
After she completed her chemotherapy and radiation treatments, Berlin also had her ovaries removed to reduce the estrogen levels in her body that had fed the tumor.
"My oncologist said if I'd gotten pregnant it would have been a death sentence," she said.
After a two-year cancer fight, Berlin said she's fearless about explaining the shortcomings of cancer screening techniques to a group of strangers.
"When I hear people talking about mammograms, I stick my nose in and tell them about my experience," she said.
Berlin says what she missed most during her battle was spending time on the ice. Her brown hair has grown back since the chemotherapy, and over the last year her strength has returned gradually. At 40 years old she's training with two coaches and looking forward to entering competitions.
"I feel like my old self again," she said.
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