At present, few imaging tools can track the progression of aggressive forms of breast, prostate or brain cancer. While magnetic resonance imaging (MRI) can show tumors, it provides no molecular information. It is therefore difficult to know the nature of the metastases.
The researchers are hopeful that these new imaging agents will help clinicians better track aggressive cancers.
Brigitte Guérin, a professor and researcher in the Department of Nuclear Medicine and Radiobiology at Université de Sherbrooke, and her colleague, Fernand Gobeil, a professor in the Department of Pharmacology and Physiology at the same university, have developed new tracers that are being used as imaging agents for positron emission tomography (PET scans). This technique involves injecting a radioactive substance that binds to tumors or metastases. To better target cancer cells, the researchers modified ligands – molecules in the body that interact with membrane receptors in cells – and combined them with the use of a radioisotope. These new ligands have the property of binding to B1 receptors, which are strongly expressed in several forms of cancer. Thanks to their radioactive component, it is possible to follow the movement of these molecules in the body and thus measure the extent of the metastasis.
The researchers have validated the stability of the new tracers in animals with tumors. They found that, in addition to acting as effective imaging agents at low doses, at higher doses they could help in treating certain cancers.
A patent has been filed and is being evaluated. The next step will be to verify the use of these tracers through human clinical trials. The researchers are hopeful that these new imaging agents will help clinicians better track aggressive cancers and select the best treatment for each case.