A PET scan, what exactly is it?

A PET (positron emission tomography) scan is a form of nuclear imaging study. Changes in the metabolism of cells are visualized using a small amount of radioactive material.

How does it work?

A PET scan is done in some forms of cancer. Cancer cells usually have an increased metabolism compared to normal cells. That means cancer cells use a lot more sugar.

With a PET scan, a small amount of radioactive sugar is injected into the blood beforehand. This radioactive sugar then concentrates on the places where the cancer cells are. The radioactivity can be seen on the images that the scan makes. In order to be able to make better quality images, a PET scan is sometimes supplemented with a CT scan.

When a PET scan?

Sometimes tumors or metastases cannot be seen on a CT or MRI scan, but other tests do indicate cancer. In such a case, a PET scan can provide clarity. In addition, the scan is used to determine the stage of the disease and to assess the effect of the therapy on cancer cells. Other abnormalities of normal metabolism can also be visualized with a PET scan.

Preparation

It is important that you fast for six hours before the test. The research will take place in the Nuclear Medicine department of the hospital.

About an hour before the examination takes place, you should drink a liter of water, tea or coffee. As a result, the kidneys will light up less on the scan. A full bladder is not necessary, you can simply pee it out again.

You can continue to use most medicines. Diabetes patients often need a different preparation, reports diabetes so always see a doctor.

It is also nice to wear comfortable warm clothing without metal buttons and zippers. It is also better to avoid heavy physical exertion prior to the examination.

The research

You will lie on a table during the examination. The table slides into a kind of tunnel, this is the scanning device. The table remains in the same position for about 15 minutes, then the table moves to the next position. Depending on the length of the scan area, scanning takes about 30 to 60 minutes. It is important to lie as still as possible. The lab technician who operates the device is in a different room. You can talk to him through an intercom.

Radioactive material

A slightly radioactive substance is used for the research. The amount of radiation is comparable to that of an X-ray and is therefore not harmful to adults. It can also do no harm in children in an adjusted dose.

The radioactive substance is only effective for a short time and is specially made and ordered for the research. The substance has no side effects and disappears completely from the body after a short time. They also do not affect the responsiveness, so after the scan you can in principle take part in traffic again.

It is best to drink plenty of fluids after the scan to discharge the radioactive substance from the body more quickly. The fluid then largely leaves the body through the urine. The rest of the radioactivity decays over time.

Result

In total, the examination can take two to three hours. After the examination, a report is made for the attending physician. He or she will discuss the result with you.

Hazards

As mentioned, the radioactive substance is not dangerous for adults. However, it is important to inform the doctor about allergic reactions, possible pregnancy, diabetes and breast-feeding. This requires extra preparations and sometimes the research cannot go ahead.

When breastfeeding, it is important to express the milk and flush it down the toilet for the first 24 hours after the examination. It is also better not to take small children on your lap just after the examination.