During a positron emission tomography (PET) scan for breast cancer, patients should expect to lie very still while their bodies are moved through an imaging machine on a mechanized table. As they pass through the machine, traces of a radioactive substance emitted into the body will be picked up by the machine and used to generate an image of the interior of the body. The image will show the location of cancer cells in the body, providing information about the size of a breast cancer and whether it has spread to neighboring tissues, including the lymph nodes.
It is possible to use a PET scan for breast cancer diagnosis, but most commonly they are used after diagnosis to collect more information about the cancer. This information is used to develop a treatment plan and prepare for surgery. Patients in treatment can also be subjected to PET scans to see if the cancer is responding to the treatment and to see how quickly the cancer responds.
In a PET scan for breast cancer, the patient lies down and is injected with a radioactive tracer. Approximately 45 minutes of rest are recommended to allow the tracer to circulate through the body. Different tissue types accumulate the tracer at different rates, allowing it to highlight cancer cells and certain other types of cells in the patient's body. The tracer is not painful or dangerous, unless a patient has a history of reacting adversely to certain medications, and screening before the PET scan for breast cancer should identify any risk factors.
Once the tracer has circulated, the patient is moved to a table that moves back and forth through a PET scanner between five and seven times. A PET scan for breast cancer can take around 45 minutes. At the same time, a CT scan may also be performed to image the inside of the body, depending on the equipment available and the specifics of a patient's case. Once the PET scan for breast cancer is over, the patient can meet with a physician to discuss the results.
The results of a PET scan for breast cancer can be discussed with an oncologist and other specialists, who can show the patient how the cancer has migrated through the body while discussing treatment options. If the scan is conducted to check on the progress of treatment, the hope is to see shrinkage in the cancer and the elimination of metastases. If the cancer is not responding, it may be a sign that the treatment needs to be adjusted or changed.
