Overview of PET/CT Fusion Technology:

A PET/CT scan combines PET and CT into one unit. PET utilizes fluorodeoxyglucose (FDG), a glucose analog labeled with radioactive fluorine, to visualize processes within the body. This glucose tracer emits positrons, or positive electrons. As the positrons encounter electrons within the body, a reaction occurs, which produces paired gamma rays that travel in opposite directions. These gamma rays are then detected by the PET scanner, which positions the FDG spatially within the patient’s body. The images produced by the PET portion of the fusion scanner contain information about the body’s utilization of glucose. Malignant or cancerous tumors utilize more glucose than most other tissues

leading to the detection of malignancy and specific tumor sites, PET is therefore a unique imaging modality in its ability to metabolically characterize biologic tissues according to their utilization of glucose and their likely malignant nature. CT uses x-rays to make cross-sectional images (called slices) of your body. The structure of body organs is more clearly visualized with CT than with conventional x-rays. The fusion scanner combines the anatomical information obtained from CT with the biological PET information to form an image that records living tissues and life processes with great precision and detail.

Clinical Applications in Oncology:

Early Detection: PET can detect cancers in their earliest stages. Since a PET scan images the metabolic activity of the body’s tissues, it can often show tumor pathology before anatomical or structural changes are evident on conventional imaging. Also, when an x-ray, MRI or CT shows a lesion, it may not accurately characterize whether it is benign or malignant. PET can often make this determination, thereby sometimes avoiding surgical biopsy when the PET scan is negative (which would indicate that the lesion is benign). Conversely, in certain cases when a PET scan is positive for cancer that has already

spread (metastasized) to other organs, a surgical cure is not possible and chemotherapy may be recommended. PET allows for far greater accuracy in the diagnosis and staging of many types of cancer. In cancers where surgery is the best course of action, the PET/CT fusion scanners provide surgeons with the ability to not only differentiate between benign and malignant tumors, but it shows them exactly where the tumors are located, thereby allowing for more targeted and often shorter surgeries, which may decrease patient morbidity.