Despite major advances in diagnosis and treatment, one in 25 Canadian women will die of breast cancer. Breast cancer patients whose tumours express (produce) high levels of the protein HER-2, in particular, have poor prognosis. This type of tumour is especially aggressive, metastatic, resistant to treatment, and has individual cells capable of withstanding adverse conditions in the tumour. Herceptin®, a drug that specifically targets HER-2, has shown remarkable results in some women with HER-2 overexpression; however, a significant number of women with this type of tumour do not respond to the drug. In order to identify aspects of HER-2 tumours that may have an impact on therapy, Dr. Mihaela Ginj is using a combination of non-invasive imaging methods to evaluate physiological functions in the tumour microenvironment, such as oxygen status, blood flow, and metabolism. This innovative study of tumour biology may enable physicians to monitor tumour response to therapy more rapidly and with greater specificity. This “personalized” approach for tumour treatment would maximize therapeutic effects and spare patients from side effects of treatments that may be ineffective. Findings from this study could have an impact on the clinical management of breast cancer in the near future.