PET/CT is a relatively new imaging tool that combines two diagnostic imaging scan techniques in one – a PET (Positron Emission Tomography) scan and a CT scan. The combined PET and CT images enhance the physician’s ability to diagnose cancer at earlier stages, including recurrent cancers, and provide a clearer assessment of response to treatments, such as radiation therapy. PET/CT is mainly used for diagnosis, staging or restaging cancer and for evaluation of treatment response. Together the two procedures provide information about the location, nature of and the extent of a tumor. It answers questions such as: where is the tumor, how big is the tumor, is it malignant, benign or due to inflammatory change, and has it spread.
PET/ CT make it possible to customize patient treatment positions. This advanced equipment is able to reconstruct individual “slices” into a 3D image of the entire area scanned, giving the most detailed high-resolution image available. Because of the lightning-fast speed, these images allow for immediate treatment planning, allowing our physicians to evaluate tumors and surrounding structures in minute detail. When PET is used to image cancer, a radiopharmaceutical (such as fluorodeoxyglucose or FDG, which includes both a sugar and a radionuclide) is injected into a patient. Cancer cells metabolize sugar at higher rates than normal cells, and the radiopharmaceutical is drawn in higher concentrations to cancerous areas. The highly sensitive PET scan picks up the metabolic signal of actively growing cancer cells.
The CT scan generates a detailed picture of internal anatomy, locating and revealing the size and shape of abnormal cancer growths. When these two results are fused together, the functional data from the PET imaging is correlated with anatomy on the CT images to give a single detailed and informative image. PET/CT allows for noninvasive evaluation of metabolic and anatomic information, providing a tremendous advantage over other currently available diagnostic tools.