A prostate-specific membrane antigen positron emission tomography (PSMA PET) scan is an imaging test that can detect prostate cancer cells using radioactive tracer.

Prostate-specific membrane antigen positron (PSMA) is a protein typically found on prostate cancer cells. A PSMA PET scan can show whether prostate cancer has spread to other parts of the body.

This article discusses the PSMA PET test for prostate cancer. It goes over what it is, how long it takes, and how accurate it is.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Prostate cancer is the most common form of cancer in people assigned male at birth in the United States. It is the second most common cause of death in males who have cancer in the U.S.

PSMA is a protein typically found on healthy prostate cells but which appears in much larger quantities on prostate cancer cells.

To perform the PSMA PET scan, a doctor injects a radioactive tracer into the arm, which the PSMA cells attract. A person then lies in a PET scan machine that creates images of the entire body.

The radioactive substance lights up PSMA cells, so a doctor can see whether any prostate cancer cells are present and exactly where they are. The scan can show whether prostate cancer has spread to other parts of the body.

In 2021, the Food and Drug Administration (FDA) approved the radioactive tracer for use in the PSMA PET scan. Since then, a number of clinics and hospitals started offering the PSMA PET scan. However, it is still a relatively new test for prostate cancer.

Currently, the primary use of the PSMA PET test is to evaluate whether prostate cancer has spread to other parts of the body.

A doctor may use the PSMA PET test for prostate cancer if a person is at high or moderate risk.

If a person with prostate cancer is at high risk, it means they have a tumor that extends outside of the prostate.

A doctor may refer to the cancer as being grade group 4 or 5. This means a pathologist has graded the cancer based on its risk of growing and spreading quickly. Grade 1 is the lowest risk level, and grade 5 is the highest.

A doctor may also use a PSMA PET scan to determine whether prostate cancer has come back after past treatment.

Studies suggest that the PSMA PET test is 27% more accurate than traditional imaging tests at detecting prostate cancer cells.

Studies also suggest that the PSMA PET test has greater sensitivity and specificity when detecting prostate cancer cells compared with other imaging methods.

Before the PSMA PET scan, a doctor will inject a radioactive tracer into the arm of the person having the scan. The person will wait for approximately 1 hour while the radioactive substance absorbs into the body.

A person will then lie inside the PET imaging machine for approximately 20 minutes while the scan takes place.

PSMA describes the protein that appears on both healthy and cancerous prostate cells. However, much larger quantities of PSMA appear on cancerous cells. PSMA sits on the surface of the cells, and a doctor can detect PSMA cells using the PSMA PET imaging scan.

Prostate-specific antigen (PSA) describes the protein that both healthy and cancerous prostate cells produce. PSA originates inside the cells and releases into the bloodstream. A doctor can detect PSA with a blood test. Blood test results will typically show a high level of PSA if a person has prostate cancer.

Both PSMA and PSA are biomarkers of prostate cancer. A cancer biomarker is a gene, protein, or other substance that can reveal important information about cancerous cells in the body.

The following are some questions frequently asked about PSMA PET scans.

What is the cost of a PSMA PET scan?

The cost of PSMA PET scans can vary in different countries. An individual should speak with a healthcare professional about any out-of-pocket costs involved with their scans.

Some insurance providers, including Medicare, may cover the cost of a PSMA PET scan for a person with prostate cancer.

Who should get a PSMA PET scan?

There are several reasons a person may want to consider having a PSMA PET scan. They may include the following:

  • A person has recently received a prostate cancer diagnosis with a high or moderate risk level.
  • A doctor believes a person’s prostate cancer has spread to other parts of the body.
  • A person has had treatment for prostate cancer in the past, and a doctor believes the cancer may have come back.

A PSMA PET test is an imaging test. It uses a radioactive tracer that attaches to the proteins that live on the cancerous cells. The tracer highlights these cancerous cells on the scan so that a doctor can determine how aggressive the cancer is and whether it has spread to other parts of the body.

If a person has recently received a prostate cancer diagnosis that is moderate to high risk, they should consider a PSMA PET scan. A doctor may also want to carry out a PSMA PET scan if they believe the cancer has spread or if a person has undergone treatment for prostate cancer in the past and the doctor believes it may have come back.

Studies suggest the PSMA PET scan to be at least slightly more accurate than traditional imaging methods at detecting prostate cancer cells.