MRI evaluation of neoadjuvant low-dose fractionated radiotherapy with concurrent chemotherapy in patients with locally advanced breast cancer

Objectives We address the diagnostic performance of breast MRI and the efficacy of neoadjuvant radiochemotherapy (NRC) treatment (NRC protocol) vs conventional neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer. Methods The NRC protocol consists of six anthracycline/taxane cycles and concomitant low-dose radiotherapy on breast tumour volume. Breast MRI was performed at baseline and after the last therapy cycle in 18 and 36 patients undergoing the NRC protocol or conventional NAC (propensity matching). Results In both groups, we observed reduced tumour dimensions after the last cycle (p<0.001), and the response evaluation criteria in solid tumours (RECIST) class directly correlated with the tumour regression grade class after the last cycle (p<0.001). Patients in the NRC group displayed a higher frequency of complete/partial response than those in the NAC group (p=0.034). 17 out of 18 patients in the NRC group met the criteria for avoiding mastectomy based on final MRI evaluatio...