Unenhanced MRI at 3T in neo-adjuvant chemotherapy

Over the past two decades, systemic neoadjuvant chemotherapy (NAC) has been used in patients with non-metastatic breast cancers [1]. The concept of NAC for operable breast cancers evolved from experience in locally advanced inoperable breast cancer. The goals of NAC in breast cancer are to treat occult systemic disease, decrease the tumor volume reducing the extent of local surgery, and increase long term survival. There are several reasons that support the advantages of NAC. First of all, systemic therapy given prior to surgery might sterilize areas of micrometastases and prevent further cancer growth after the primary tumor is resected [2]. This would be especially true considering the hypothesis that breast surgery could release tumor cells and stimulate the growth of occult micro-metastases through mechanisms such as angiogenesis [3,4]. Another positive aspect of NAC is the possibility to reduce the size of the primary tumor, which allows higher rates of breast-conserving surgery and/or reduces local recurrence rates. Last, the efficacy of NAC can be used as an in vivo assay of drug sensitivity/resistance. In fact, NAC requires an optimal assessment of response to cytotoxic drugs in vivo, which is not only clinically relevant but also critical in terms of research efforts directed to the assessment of chemo resistance and response. Accurate assessment of the neoadjuvant response is a critical element in monitoring and assessing treatment strategies. Considering the high toxicity of chemotherapeutic drugs, early assessment of therapeutic response of the tumor is essential for patient management, as NAC is associated with significant morbidity and reduced quality of life [5,6]. Nowadays, contrast enhanced MRI is considered the most reliable imaging technique in the early assessment of response to NACand it is commonly used in many centers in monitoring NACresponse in patients affected by breast cancer. Several studies have