Locally advanced breast cancer (LABC) is usually treated with neoadjuvant chemotherapy followed by surgery and radiation. At present, monitoring of tumour responses to chemotherapy is primarily carried out using physical examination at the beginning of each chemotherapy cycle. Differentiating viable tumour tissue from inflammation or fibrotic scar tissue can be difficult. There is a growing body of evidence that newer imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI) may be better at determining whether or not the tumour is actually shrinking. The purpose of this study is to determine the sensitivity and specificity of PET, MRI and ultrasound in evaluating tumour responses to chemotherapy in patients with LABC and compare this with physical examination, which is the current standard of care.