Proton MR spectroscopy with choline peak as malignancy marker improves positive predictive value for breast cancer diagnosis: preliminary study.
OBJECTIVE
To prospectively evaluate the diagnostic performance of magnetic resonance (MR) spectroscopy in patients with suspicious lesions or biopsy-proved cancers at MR imaging by using histologic findings as the reference standard.


METHODS
After institutional review board approval and informed consent were obtained for this HIPAA-compliant study, breast MR spectroscopy was performed in patients with suspicious or biopsy-proved malignant lesions measuring 1 cm or larger at MR imaging. Single-voxel MR spectroscopy data were collected from a single rectangular volume of interest that encompassed the lesion. MR spectroscopy findings were defined as positive if the signal-to-noise ratio of the choline resonance peak was greater than or equal to 2 and as negative in all other cases. MR spectroscopy findings were then compared with histologic findings.


RESULTS
A total of 56 patients (age range, 20-77 years) with 57 lesions were imaged. The median lesion size at MR imaging was 2.3 cm (range, 1-15 cm). Histologically, 31 (54%) of 57 lesions were malignant, and 26 (46%) were benign. A choline peak was present in 34 of 57 lesions (including all cancers) and in three of 26 benign lesions, giving MR spectroscopy a sensitivity of 100% and a specificity of 88%. In 40 lesions of unknown histologic type, the use of MR spectroscopy as an adjunct to MR imaging would have significantly (P<.01) increased the positive predictive value of biopsy from 35% to 82%. If biopsy had been performed only on those lesions with a choline peak at MR spectroscopy, biopsy may have been spared in 23 (58%) of 40 lesions, and none of the cancers would have been missed.


CONCLUSIONS
Proton MR spectroscopy was successfully incorporated into breast MR imaging studies for lesions measuring 1 cm or larger. This technique may be useful in reducing the number of lesions detected at MR imaging that require biopsy.
Bartella
Lia
L
Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10021, USA. bartelll@mskcc.org
Morris
Elizabeth A
EA
Dershaw
D David
DD
Liberman
Laura
L
Thakur
Sunitha B
SB
Moskowitz
Chaya
C
Guido
Jennifer
J
Huang
Wei
W
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002794:Choline / Q000032:analysis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000706:statistics & numerical data; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011522:Protons; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D011522:Protons; D002794:Choline