Surgical Planning after Neoadjuvant Treatment in Breast Cancer: A Multimodality Imaging-Based Approach Focused on MRI

SIMPLE SUMMARY: The effectiveness of neoadjuvant treatment has led to an expansion of its indications from locally advanced to highly chemo-sensitive early-stage breast cancers, aiming to increase conservative treatments, in place of more invasive surgery, and to improve long term outcomes. At the same time, the continuous development of diagnostic techniques necessitates continuous updating, due to their importance in tumoral staging and in the prediction of the response to treatment, as well as in surgical planning. With our review, we sought to discuss the strengths of the various imaging modalities; in particular, the role of magnetic resonance imaging, which is still the center of scientific debate in this setting. Moreover, we analyzed the evolution of surgical approaches to breast cancer in patients treated with neoadjuvant chemotherapy. ABSTRACT: Neoadjuvant chemotherapy (NACT) today represents a cornerstone in the treatment of locally advanced breast cancer and highly chemo-sensitive tumors at early stages, increasing the possibilities of performing more conservative treatments and improving long term outcomes. Imaging has a fundamental role in the staging and prediction of the response to NACT, thus aiding surgical planning and avoiding overtreatment. In this review, we first examine and compare the role of conventional and advanced imaging techniques in preoperative T Staging after NACT and in the evaluation of lymph node involvement. In the second part, we analyze the different surgical approaches, discussing the role of axillary surgery, as well as the possibility of non-operative management after-NACT, which has been the subject of recent trials. Finally, we focus on emerging techniques that will change the diagnostic assessment of breast cancer in the near future.