Abstract P3-03-01: 3D mapping of total choline in human breast cancer using high-speed MR spectroscopic imaging at 3T: initial experience during neoadjuvant therapy

OBJECTIVE: To assess the feasibility of quantitative high-speed MR spectroscopic imaging (MRSI) of total Choline (tCho) as an adjunct to dynamic-contrast enhanced MRI to improve lesion characterization and monitor treatment response in patients undergoing neoadjuvant chemotherapy (NAC). METHODS: Twelve patients with infiltrating ductal carcinoma (Table 1) were studied using a clinical 3T MR scanner (Siemens, Erlangen, Germany) equipped with 8- and 16-channel breast array (Hologic Inc., Bedford, MA). Four patients were studied before NAC. Four patients were studied once during NAC. Two patients were studied before and within 2–7 days of treatment initiation. One of these patients participated in an additional scan after 5 months of treatment. Two additional patients were studied at 3 time points during NAC. Measurements were performed using PRESS prelocalized 3D Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) using TR/TE=2000ms/135ms, matrix size up to 32×16×8, voxel size = 1cc, and total acquisition time of 10 minutes (including water reference scan). Additional data were collected at TE 60 ms to enhance sensitivity for detecting tCho and J-coupled resonances. TE-averaging (8 steps, DTE: 2.5 ms) was employed to minimize gradient sideband artifacts. Quantification of tCho in reference to tissue water was performed using spectral fitting and relaxation correction. RESULTS: Strongly elevated tCho with maximum concentration up to 5.3 mmol/kg was measured in 9 patients with enhancing lesions larger than 2 cc volume (Table 2). Decreases in tCho were measured in all four patients who were followed during neoadjuvant chemotherapy. Decreases in tCho were measurable during the first week of neoadjuvant treatment in responders, consistent with previous studies. Our preliminary data also indicate that the combination of concentration and spatial extent of detectable tCho may be the most sensitive marker of treatment response. CONCLUSION: This study demonstrates feasibility of quantitatively mapping tCho in invasive breast carcinoma using high-speed MRSI. The long-term goals are to utilize high-speed MRSI as an early predictor of treatment failure in women undergoing neoadjuvant therapy (i.e. chemotherapy, endocrine therapy or biologic therapy) for breast cancer and to develop an improved screening protocol for high-risk patients. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-03-01.