Recent developments in imaging devices provide researchers with powerful tools to detect cancers and explore the impact of therapy on tumour cells. This research program plans to leverage the strengths of positron emission tomography combined to computed tomography (PET/CT) to characterize and rapidly assess response to therapy in 3 common cancers (breast, prostate, and lymphoma) and combine this information with other predictors of aggressiveness and treatment failure. PET/CT imaging is a powerful technique that combines the strenghts of a PET scanner (which can measure tumor receptors and metabolic activity) with those of a CT scanner (which provides detailed images of a patient's anatomy). The combination of both approaches could rapidly identify patients that are likely to fail conventional therapy and offer them alternatives that are better suited to the nature of their cancer. The research program is designed around 3 core themes. The first research them focuses on the development of methods to predict the outcome of patients with breast cancer who are treated with chemotherapy or hormone therapy. We will pursue ongoing work to develop animal models of breast cancer and imaging methods to monitor response of these tumors to chemotherapy and hormone therapy. We will also conduct clincial studies to correlate the results of imaging studies performed with PET/CT with outcome and response to therapy. The second theme focuses on the development of new probes that target specific proteins that are overexpressed at the surface of breast and prostate tumors. These probes might eventually be translated into clinical studies as breast and prostate cancer diagnostic agents for use with PET/CT, or even for therapy by tagging them with radioisotopes that can destroy tumor cells by proximity. The last theme proposes practical research studies of immediate clinical interest. We will assess the accuracy of PET/CT imaging in staging prostate cancer (with 2 radiopharmaceuticals designed to assess tumor lipid synthesis and bone turnover). We will also extend to the Vancouver site an ongoing study that assesses PET/CT imaging to predict the early response to chemotherapy in large cell lymphoma.