Assessment of therapeutic response of locally advanced breast cancer (LABC) patients undergoing neoadjuvant chemotherapy (NACT) monitored using sequential magnetic resonance spectroscopic imaging (MRSI)

The potential of total choline (tCho) signal‐to‐noise ratio (SNR) (ChoSNR) and tumor volume in the assessment of tumor response in locally advanced breast cancer (LABC) patients (n = 30) undergoing neoadjuvant chemotherapy (NACT) was investigated using magnetic resonance spectroscopic imaging (MRSI) and conventional MRI at 1.5 T. Experiments were carried out sequentially at four time‐points: prior to therapy and after I, II and III NACT and ChoSNR, and the tumor volume was measured. The MR response was compared with the clinical response. Sequential data of 25 patients were retrospectively analyzed by classifying them as clinical responders and non‐responders. In 14 responders, the pre‐therapy ChoSNR was 7.8 ± 5.1. In 10/14 responders, no choline was observed after III NACT while in the remaining four patients the ChoSNR was reduced to 3.6 ± 1.1 (p