Study to Evaluate the Feasibility of 13-C Pyruvate Imaging in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

Overview

Breast cancer is the second most common form of cancer in women and the most frequent cause of death. Despite breast screening programs, a substantial number of women are diagnosed with cancers greater than 2 cm in size or locally advanced disease, which is best treated with neoadjuvant chemotherapy (NAC) prior to surgery. Approximately 10% of women diagnosed with breast cancer annually will have locally advanced breast cancer, defined as stage III disease, where the cancer has either spread to regional lymph nodes and/or other tissue in the area of the breast, but not to distant sites. NAC offers the advantages of downstaging the disease, potentially reducing the extent of surgery. Presently, gadolinium enhanced MRI is the standard test used to monitor disease response to chemotherapy, and demonstrates changes in tumour size and extent between pre-NAC and post-NAC. Unfortunately, changes in tumour size may occur late in treatment regimen, thus producing false-negative results on early magnetic resonance imaging (MRI). Therefore, newer imaging techniques beyond anatomical imaging are needed to identify tumours that are unresponsive to chemotherapy and potentially change treatment plan early on to avoid significant morbidity associated with prolonged chemotherapy. A novel MRI technique utilizing hyperpolarized pyruvate has the potential to detect pathophysiological response early in the treatment regimen and would therefore allow for earlier identification of nonresponders and subsequent early modification of treatment regimens, if necessary.

Objectives: Primary Objective To assess feasibility of of acquiring time resolved, 3D 13C pyruvate MR images of breast cancer requiring neoadjuvant chemotherapy after administration of hyperpolarized 13C pyruvate. Secondary Objectives 1. To determine the diagnostic accuracy of time resolved, 3D 13C pyruvate MR imaging after administration of hyperpolarized 13C pyruvate for differentiating breast cancer from normal breast parenchyma. 2. To spatially correlate lactate seen on hyperpolarized 13C MR to anatomic imaging with conventional MRI. 3. To assess if hyperpolarized 13C pyruvate MR can differentiate between tumour necrosis versus viable tumour 4. To acquire statistical information to help design, fund, and power future clinical studies with larger patient populations. Overall Study Design This is a pilot prospective, single-institution study in participants who will receive NAC. Participants will be first informed of the study by personnelle within the patient's circle of care. If the patient expresses interest in participating in the study, the study's Clinical Research Coordinator will approach the patient to provide further information, answer any questions, provide study documentation, as well as to obtain informed consent if agreeable. Clinical procedures will be completed at Sunnybrook Health Sciences Centre (SHSC) under the supervision of medically trained personnelle. \- Population: A total of 13 participants will be recruited for this study. Prior to the first study research MRI scan, we will scan up to 3 volunteer participants with a known breast malignancy (Group 1). These participants will not have hyperpolarized 13C pyruvate administered. They will be scanned with a 13C phantom in order to test the functionality of the 13C coil. Subsequently, up to 10 volunteer participants with breast cancer requiring NAC, between 18 and 80 years of age with pathology- and imaging-confirmed breast cancer requiring NAC will be studied (Group 2). Imaging confirmation involves highly suspicious masses on mammography and/or ultrasound. Pathology confirmation involves image-guided core biopsy of the suspicious mass. * Design: Each participant will receive one research MRI scan on the 3T MRI scanner prior to NAC. This visit will occur separately from the patient's clinical dynamic contrast enhanced (DCE) MRI. * Scan Timing: The research MRI exam will be scheduled before the initiation of NAC, and within 5 days prior to, or following, the clinical MRI scan.