Researchers Harness Radioactivity for New Cancer Treatments

Medical researchers from the University of Alberta are pushing the boundaries of nuclear medicine. They are finding new ways to harness technology, new knowledge about the nature of cancer and the radioactive nature of elements to learn more about how cancer affects individual patients and improve their treatments.

X-rays, CAT scans and MRIs give two- or three-dimensional views of body structures, allowing doctors to see inside patients to identify structural abnormalities caused by disease. On the other hand, nuclear medicine uses safe radioactive materials to create images of body functions at the molecular level, particularly in patients with cancer.

The newest imaging technology combines PET scans (positron emission tomography) with CAT scans to provide a 3D “map” of metabolic activity in cells – the basic process by which cells transform glucose into energy. This diagnostic tool called molecular imaging is especially valuable in pinpointing tumours very early, for conducting cancer research into the effects of cancer on the body, and for selecting the right treatment for the right patient at the right time.

The PET Centre at Edmonton’s Cross Cancer Institute is operated by the U of A and Alberta Health Services. It is the leading centre in Canada in the research and application of molecular imaging for cancer. Several principal investigators from the U of A’s Oncologic Imaging Division in the Faculty of Medicine & Dentistry are carrying out cutting-edge discovery research at the Cross to advance the science of nuclear medicine.

These academic clinicians and scientists are also involved in many different studies using molecular imaging to “see” and learn about the behaviour of various kinds of tumour cells, and how the cells respond to experimental chemotherapy drugs and/or radiation treatments.

“We think we can use molecular imaging to predict how a tumour is going to behave and how a patient is going to respond to a course of treatment, and learn very early if the treatment is working or if it should be changed,” says Dr. Alexander (Sandy) McEwan, professor and chair of the faculty’s Department of Oncology who also leads the PET Centre.

“That’s what a lot of our research is designed to test,” adds McEwan, a molecular imaging specialist and past president of the international Society of Nuclear Medicine in 2007-08.

Molecular imaging works this way: Radioactive isotopes(unstable forms of elements)that decay quickly are combined with organic molecules to produce what is called a radiopharmaceutical. The most widely used one is FDG, which combines glucose with a radioactive fluorine isotope. After a tiny amount of this “radioactive sugar” is injected into the patient, a special camera (PET scanner) detects where it is being used in the body.

The camera takes pictures which follow the path of the radiopharmaceutical as it is processed by the body. Because cancer cells are heavy users of glucose, increased concentrations of FDG end up in tumours, making them visible.