Preliminary study of early response to neoadjuvant chemotherapy after the first cycle in breast cancer: comparison of 1H magnetic resonance spectroscopy with diffusion magnetic resonance imaging

Purpose. The aim of this study was to assess the efficacy of single-voxel H-1 magnetic resonance spectroscopy (MRS) at 1.5 T to evaluate early responses to neoadjuvant chemotherapy after the first treatment in breast cancer patients and to compare it to measurements of apparent diffusion coefficient ( ADC) values derived from diffusion-weighted magnetic resonance imaging (MRI). Materials and methods. Nine patients with breast cancer who were scheduled to receive neoadjuvant chemotherapy were recruited. MR examination after the first cycle was scheduled for a few days before the administration of the second dose. Results. Two patients were excluded from the study because their regimen was changed after the first cycle. MRS before chemotherapy demonstrated the presence of choline (Cho) at 3.22-3.23 ppm in six cases and at 3.27 ppm in one case. Diffusion-weighted MRI before chemotherapy demonstrated a localized high-signal lesion in all cases. The change of the integral value of Cho after the first cycle of chemotherapy showed a positive correlation with the change in lesion size (r = 0.91, P = 0.01), whereas no correlation was observed between the change of ADC values after the first cycle and the change in lesion size (r = 0.45, P = 0.32). Conclusion. MRS after the first cycle may be more sensitive to diffusion-weighted MRI to predict the pathological response.