Magnetic Resonance MR Spectroscopy Could Reduce Breast Biopsies

Magnetic Resonance
MR Spectroscopy Could Reduce Breast Biopsies
Oct. 05, 2007
Proton magnetic resonance spectroscopy, or MRS, used in conjunction with magnetic resonance can help diagnose breast cancer while reducing the number of false-positive results and biopsies, according to a new study.
Research has shown that MR can detect breast cancer missed on mammography in high-risk women. However, the technology results in a significant number of false-positive results and biopsies. Currently, approximately 80 percent of breast lesions biopsied turn out to be benign, according to researchers.
The addition of proton MRS to the examination has the potential to reduce false-positive results by measuring levels of choline compounds, which are markers of an active tumor.
In the study, researchers performed proton MRS on 32 nonmass enhancing breast lesions in 32 women, ages 20 to 63 years. Nonmass enhancing lesions are characterized by enhancement of an area that is not a mass or lump and may extend over large or small regions. These types of lesions frequently pose a dilemma to the radiologist when evaluating the breast for the presence of cancer, especially in premenopausal women, because they occur with benign hormonal changes, but also can signify malignancy. Biopsy is often required to distinguish benign nonmass lesions from cancer.
Of the 32 women, 25 had lesions that had been labeled suspicious at MR.
There were positive choline findings in 15 of 32 lesions, including all 12 cancers, giving proton MRS a specificity of 85 percent and a sensitivity of 100 percent. Proton MRS as a supplement to breast MR imaging increased the positive predictive value of biopsy for MR-detected nonmass lesions from 20 percent to 63 percent.
If researchers had biopsied only the lesions with positive choline findings, then 17 of 25 lesions, or 68 percent, may have been spared invasive biopsies and none of the cancers would have been missed.
"By performing MR spectroscopy of the suspicious lesion after an MR scan, we can noninvasively see which tumors show elevated choline levels and are likely malignant," said Lia Bartella, M.D., from the Memorial Sloan-Kettering Cancer Center in New York City, and colleagues. "This chemical information added to the information provided by MR can eliminate the need for biopsy to find out what the lesion is made of." The study appears in the October issue of Radiology.
Proton MRS adds only 10 minutes to a standard MR exam, according to Dr. Bartella, who sees a future for the procedure in routine diagnostic breast MR procedures.
"Our study data show that the information obtained at proton MRS may decrease the number of biopsy recommendations for benign enhancing non-mass lesions," she said.
By Laurie Volkin and Richard S. Dargan, ASRT