Multiparametric Magnetic Resonance Imaging, Spectroscopy and Multinuclear ( 23Na) Imaging Monitoring of Preoperative Chemotherapy for Locally Advanced Breast Cancer

Abstract

The aim of this prospective study was to investigate using multiparametric and multinuclear magnetic resonance imaging during preoperative systemic therapy for locally advanced breast cancer. Women with operable stage 2 or 3 breast cancer who received preoperative systemic therapy were studied using dynamic contrast-enhanced magnetic resonance imaging, magnetic resonance spectroscopy, and ²³Na magnetic resonance. Quantitative metrics of choline peak signal-to-noise ratio, total tissue sodium concentration, tumor volumes, and Response Evaluation Criteria in Solid Tumors were determined and compared to final pathologic results using receiver-operating characteristic analysis. Hormonal markers were investigated. Statistical significance was set at P < .05. Eighteen eligible women were studied. Fifteen responded to therapy, four (22%) with pathologic complete response and 11 (61%) with pathologic partial response. Three patients (17%) had no response. Among estrogen receptor-positive, HER2-positive, and triple-negative phenotypes, observed frequencies of pathologic complete response, pathologic partial response, and no response were 2, 5, and 0; 1, 4, and 0; and 1, 1, and 3, respectively. Responders (pathologic complete response and pathologic partial response) had the largest reductions in choline signal-to-noise ratio (35%, from 7.2 ± 2.3 to 4.6 ± 2; P < .01) compared to nonresponders (11%, from 8.4 ± 2.7 to 7.5 ± 3.6; P = .13) after the first cycle. Total tissue sodium concentration significantly decreased in responders (27%, from 66 ± 18 to 48.4 ± 8 mmol/L; P = .01), while there was little change in nonresponders (51.7 ± 7.6 to 56.5 ± 1.6 mmol/L; P = .50). Lesion volume decreased in responders (40%, from 78 ± 78 to 46 ± 51 mm³; P = .01) and nonresponders (21%, from 100 ± 104 to 79.2 ± 87 mm³; P = .23) after the first cycle. The largest reduction in Response Evaluation Criteria in Solid Tumors occurred after the first treatment in responders (18%, from 24.5 ± 20 to 20.2 ± 18 mm; P = .01), with a slight decrease in tumor diameter noted in nonresponders (17%, from 23 ± 19 to 19.2 ± 19.1 mm; P = .80). Multiparametric and multinuclear imaging parameters were significantly reduced after the first cycle of preoperative systemic therapy in responders, specifically, choline signal-to-noise ratio and sodium. These new surrogate radiologic biomarkers maybe able to predict and provide a platform for potential adaptive therapy in patients.