MR Spectroscopy Increases Breast Cancer Detection Accuracy
Magnetic resonance imaging (MRI)
that would have been missed by traditional
and is, therefore, becoming a more commonly used screening technique, especially for women at high risk. But a major downside of MRI is that it is too sensitive, detecting many breast changes that turn out to be normal variations or perfectly benign (ie, noncancerous). This has resulted in many unnecessary
To address this concern, researchers have suggested using magnetic resonance (MR) spectroscopy, which allows radiologists to see the chemical makeup of the tumor. Cancerous tumors tend to produce elevated levels of choline, which can be detected on MR spectroscopy.
A new study in the June issue of
found that the addition of MR spectroscopy to MRI breast cancer screening significantly reduced the need for biopsy and missed no breast cancers.
About the Study
Researchers from the Memorial Sloan-Kettering Cancer Center in New York evaluated 56 women with 57 breast tumors measuring one centimeter or more. The participants underwent MRI of the breast, followed by MR spectroscopy. All of the participants had a breast biopsy to determine if the tumor was cancerous.
The biopsies showed that 31 (54%) of the tumors were cancerous and 26 (46%) were benign. MR spectroscopy detected a positive choline peak (indicating probable cancer) in 34 tumors, including all 31 cancerous tumors and three benign tumors. When the researchers excluded cancers that were diagnosed by biopsy before the study began, they concluded that the addition of MR spectroscopy resulted in 58% fewer biopsies than MRI alone without missing any cancers.
This study is limited because the sample size of 56 participants was relatively small. And the results cannot be generalized to women with tumors smaller than one centimeter.
How Does This Affect You?
These findings suggest that the addition of MR spectroscopy to MRI breast cancer screening may decrease the number of unnecessary biopsies, without missing any breast cancers. This is significant, since a reduction of unnecessary breast biopsies is a major objective of cancer screening programs. Unnecessary biopsies are associated with medical complications, result in considerable stress and anxiety, and cost money and time.
Will radiologists now begin using MR spectroscopy with MRI breast cancer screening? Probably not just yet. The researchers spent a lot of time and used the help of a physicist to set up the MR spectroscopy equipment. A less rigorous setup technique may result in inaccuracies that could lead to missed cancers—a risk that is unacceptable. If this technique proves as successful in future studies, it is likely that medical technology companies will invest in the design and production of spectroscopy equipment as convenient and easy to use as regular MRI or even conventional mammography.
Until MR spectroscopy is ready for a clinical setting, discuss the risk of false-positive results
having a breast MRI (or any other screening test) with your doctor. Just knowing that a positive result is often incorrect may help put your mind at ease.
American Cancer Society
National Cancer Institute
Bartella L, Morris EA, Dershaw DD, et al. Proton MR spectroscopy with choline peak as malignancy marker improves positive predictive value for breast cancer diagnosis: preliminary study.