PET/CT Unit Positron Emission Tomography in combination with Computed Tomography (PET/CT) provides a more accurate evaluation for cancer than either modality alone. CT provides the roadmap of precise anatomic detail (size and location of the tumor, mass, etc.), and a PET scan overlay identifies abnormal metabolic activity (cellular activity of the tumor, mass, etc.). Anatomic CT scanners send a small column of x-rays through the body, which are measured by detectors in the CT scanner. A computer algorithm processes the information to produce pictures of the body's internal structures. Metabolic PET images take advantage of the fact that metabolically active organs and rapidly growing tumors consume glucose (sugar) at high rates. Fluorodeoxyglucose (FDG) a sugar similar to glucose is tagged with the radioactive fluorine (F18). As the FDG is used, it emits positrons. These positrons collide with electrons, giving off gamma rays, and a computer converts the gamma rays into images. These images demonstrate metabolic "hot spots." Large studies have shown that the following cancer types benefit most from this technology: breast, cervical, ovarian, esophageal, colorectal, lung, head and neck, sarcoma, melanoma and lymphoma. PET/CT can be used to determine the extent of disease or the location of disease for biopsy, surgery or treatment planning. Using both modalities together enables the radiologist to make a more precise interpretation at an earlier time point. Later, it can be used to assess the response to treatment and detect residual or recurrent disease at an earlier time point. In this way, the patient may avoid additional biopsies. What to Expect The entire examination usually takes less than 30 minutes. The tagged FDG solution is injected into a vein. Images are then taken in a machine that looks like a traditional CT machine, in which a table slides into a detector that looks like a large donut. It is important that the patient remain still during the test since the two images must be superimposed and the detection of subcentimeter disease is a desired benefit of this technology. Preparation No preparation is necessary Information The Radiology Information Resource for Patient PET/CT Locations • Memorial Regional Medical Center • Richmond Community Hospital • St. Francis Medical Center • St. Mary's Hospital Commonwealth Radiology, P.C. 1508 Willow Lawn Dr. Ste. 117 Richmond, Virginia 23230 804-288-8327 www.commonwealthradiology.com