Neoplastic tissue contains elevated levels of choline-containing metabolites (tCho) 12. The purpose of this study is to determine whether magnetic resonance spectroscopy (MRS) with magnetic resonance imaging (MRI) can be a noninvasive technique for determining whether a breast abnormality is benign or malignant and to monitor response to neoadjuvant chemotherapy (CT).

Women scheduled for a breast biopsy or scheduled to CT were recruited for our study. All studies were done with a 4 T MRI/MRS scanner. A baseline scan was done prior to the start of CT and 24 hours after CT. Suspicious lesions were identified and measured with a fat-suppressed high-resolution 3D FLASH image (Gd-TPA, 0.1 mmol/kg). Concentrations of tCho were quantified 3. Each scan was interpreted by evaluation of lesion size, architecture, signal intensity, and tCho.

Twenty-six out of 69 patients had infiltrative ductal carcinoma, 10/69 patients had infiltrative lobular carcinoma, 3/69 patients had ductal carcinoma in situ, 1/69 patients had lobular carcinoma in situ, and 29/69 patients were found to have benign breast lesions. Eight patients have been through CT. Tumor response was seen in six patients. MRS could detect decreased [tCho] within 24 hours after CT. In the six patients with decreased [tCho] at 24 hours, 100% showed diminished tumor size measured by MRI after 9 weeks of CT. However, the two patients with sustained or elevated [tCho] at 24 hours failed to have response to CT.

Based on these results, we expect that the addition of MRS to MRI will provide a noninvasive technique for determining whether a breast abnormality is benign or malignant. Furthermore, the [tCho] measured at 24 hours appears to predict response to CT.