About PET/CT

Cancer is a terrible and unfortunately all too common disease that will strike one in every three people. According to the American Cancer Society, approximately 1.5 million new cases of cancer will be diagnosed this year alone in the United States. It is one of medicine’s greatest challenges to accurately detect and treat this devastating disease. The latest and most advanced weapon in this fight has been the development of the PET/CT. This machine has changed the way we are able to not only detect cancer early, but with it we can follow the progression of cancer, and monitor the success of any prescribed therapy.

What exactly is a PET/CT?

Upon first hearing about it, some might think a PET/CT is a test for cats and dogs. PET in this instance does not refer to man’s best friend, but is instead an acronym for Positron Emission Tomography. This is how it works: (1) Active cancer cells burn the sugar glucose at unusually high rates; (2) Patients to be scanned are given an injection of radiolabeled glucose that the PET scanner can detect; ; (3) The patient waits one hour for thesugar to attach to the cancer cells (4) The entire body is then scanned; (5) The cancer cells will eat more of the sugar than the rest of the body and areas with the highest concentration of radiolabeled sugar are suspicious for cancer. From this, we can see where cancer has been most active in the body.

So why are we doing a CT?

A CT scan (also called CAT scan) is a machine that uses X-rays to take incredibly detailed images of the inside of the body. CT imaging provides excellent anatomic information. However, it doesn’t show which cells are active, or just how active they are. Once we are able to combine the two images (the PET and CT scans) we can accurately detect not only where we are in the body but which cells are most likely to have cancer.

What are common uses of the PET/CT?

This modality is used in early detection of cancer and to determine whether a cancer has spread in the body. Follow up studies are used to assess the effectiveness of a treatment plan, such as surgery and/or chemotherapy. Additionally, it is used to determine if a cancer has returned after treatment. I am often surprised by how many people return afterwards on their own accord, just to be sure the cancer is really gone. I was once told by a patient, “There’s just no price you can put on peace of mind for a cancer survivor.” Most cancers can be detected by a PET/CT including breast cancer, ovarian cancer, and lymphoma, just to name a few.

I am diabetic. Is it dangerous to give me radiolabeled sugar?

Diabetic patients can receive the radiolabeled sugar without any problems. However, for the test to have maximum effectiveness, it is very important for patients to control their blood sugar. If the blood sugar is over 225, the examination is very limited for interpretation, and may need to be rescheduled.

How do I prepare for this test?

atients are instructed to eat a low carbohydrate, high protein meal the night before. Our patients should not eat anything after midnight and have nothing to eat or drink the morning of the test (except water). Patients should not exercise or engage in heavy lifting the day before the examination. Patients who are diabetic can eat the morning of the test and take their medication. They will be scheduled for their examination in the afternoon. Patients should dress comfortably, wearing clothes without heavy buckles, zippers or metal snaps. Sweat shirt and sweat pants are ideal. Metal objects including jewelry, eyeglasses, dentures and hairpins may affect the CT images and should be left at home or removed prior to your exam.

Who interprets the images of a PET/CT?

A radiologist will interpret the images and forward a detailed report and colored pictures or a CD with your images to your referring physician within 24 hours. At our office, we have two radiologists review each and every PET/CT; one with specialized training in nuclear medicine and another with specialized training in body CT scans. Four eyes are always better than two.

What kind of PET/CT does your facility have?

For convenience, our office has all modalities under one roof. We have a brand new, state-of-the-art PET/CT machine located in a dedicated wing with a spacious separate waiting room and refreshments provided for the comfort of our patients and their families.