Prostate cancer is one of the most common types of cancer among men. Approximately
If you have prostate cancer, the stage of the disease will affect your recommended treatment plan and outlook.
Prostate cancer is easier to treat in its early stages, before it has spread beyond the prostate gland. If the cancer has spread to other parts of your body, it’s known as metastatic prostate cancer.
The PSMA PET scan is a new type of imaging test that can help doctors learn whether prostate cancer has spread.
Researchers have found this scan may be more accurate than conventional testing approaches for diagnosing metastatic prostate cancer.
Take a moment to learn more about the PSMA PET scan.
The PSMA PET scan is a test that can help your doctor learn if and where prostate cancer has spread outside your prostate gland, including to your lymph nodes, other organs, or bones.
PET scans are a type of imaging test that use special dye with radioactive tracers to make cancer cells show up more clearly.
The PSMA PET scan uses radioactive tracers that bind to prostate-specific membrane antigen (PSMA). This is a protein that’s found in high levels on the surface of prostate cancer cells.
The Food and Drug Administration (FDA) has recently approved the following PSMA-targeted tracers:
Researchers are studying other PSMA-targeted tracers, which might be approved in the future.
Your doctor might order a PSMA PET scan if you’ve recently received a new diagnosis of prostate cancer and they think it may have spread to other parts of your body. Or your doctor may use it to get a better idea of where prostate cancer has spread.
Prostate cancer is usually diagnosed in its early stages, before it has spread. However, some people are at heightened risk of metastatic prostate cancer.
“Your doctor might order PSMA PET-CT at the time you are diagnosed with prostate cancer if you have any risk factors for metastatic disease,” Dr. Michael Feuerstein, a urologist at Lenox Hill Hospital in New York City, tells Healthline.
According to Feuerstein, doctors use the following measurements to assess the risk of metastatic prostate cancer:
- Prostate-specific antigen (PSA). PSA is a protein made by the prostate that’s found in the semen and blood. It tends to be elevated in people with prostate cancer. A PSA blood test is one of the first tests doctors order to diagnose prostate cancer. You’re considered at risk of metastatic prostate cancer if you have a PSA blood level of 20 or higher.
- Gleason grade. This system assigns a score to classify how many abnormal prostate cancer cells are found in a tissue biopsy. A Gleason grade of 7 (3+4) or higher puts you at higher risk of metastatic prostate cancer.
Your doctor might also order the PSMA PET test if you still have detectable prostate cancer after undergoing surgery to treat it, says Feuerstein.
Additionally, your doctor might order this test if you’ve been successfully treated for prostate cancer, but tests suggest the disease has come back.
If blood tests show rising PSA levels, that’s a sign the cancer has returned.
In some cases, your doctor might order more conventional tests instead of the PSMA PET scan. Conventional tests for metastatic prostate cancer typically include a combination of CT, MRI, or bone scans.
Your doctor might order conventional tests if the PSMA PET scan technology isn’t available in your region or your insurance plan doesn’t cover it, says Feuerstein.
Multiple studies have found that the PSMA PET test appears to be more accurate than conventional tests for diagnosing metastatic prostate cancer.
Researchers found that the PSMA PET scan was 27 percent more accurate at detecting cancer in the pelvic lymph nodes or metastases outside the prostate than the conventional tests.
Another 2020 study evaluated men with prostate cancer who had received staging with a conventional combination of CT, MRI, and bone scans followed by PSMA PET scans. The PSMA PET scans increased the level of confidence in the staging results by 20 percent.
Both these studies found that in multiple cases, results from the PSMA PET scan led to changes in people’s recommended treatment plans.
The PSMA PET scan usually takes about 2 hours, although timing may vary.
To conduct a PSMA PET scan, a nurse or technician will inject a special dye with a radioactive tracer into one of your veins. They will ask you to wait approximately 30 to 60 minutes to allow the dye to travel throughout your body.
Next, they will ask you to lie down on a padded exam table. They will slide the table through a PET-CT or PET-MRI scanner to create images of your body. This scan may take 30 minutes or longer to complete.
After the scan is finished, a specialist will review the images and report the results to your doctor. Your doctor will share the results with you.
Ask your doctor how long it will take to receive the results of the scan.
The PSA test is different from the PSMA PET scan.
The PSA test is a blood test that measures the level of PSA in your blood. PSA is a protein produced by cells in your prostate gland. High levels of PSA are often a sign of prostate cancer.
The PSMA PET scan is used after PSA testing if your doctor isn’t sure if or where prostate cancer has spread. It can more accurately pinpoint where prostate cancer cells are located throughout the body.
Your doctor may order a PSA blood test to:
- screen for prostate cancer if you don’t have symptoms of the disease
- determine whether further tests are necessary to diagnose prostate cancer if you do have symptoms of the disease
- check for signs that prostate cancer has come back if you’ve received successful treatment for the disease
PSA blood test results are not enough to diagnose prostate cancer or learn whether it has spread or returned. If you have high levels of PSA, your doctor will order other follow-up tests to develop an accurate diagnosis.
Your doctor will only order a PSMA PET scan if they think you may have prostate cancer that has spread beyond the prostate gland.
The PSMA PET scan is an imaging test that can help your doctor learn whether prostate cancer has spread beyond your prostate gland to other parts of your body or returned following successful treatment.
If you have prostate cancer that has spread, it’s known as metastatic prostate cancer. The recommended treatments for prostate cancer vary, depending on whether the disease has spread.
Research suggests that the PSMA PET scan appears to be more accurate than conventional tests for diagnosing metastatic prostate cancer. This scan may help your doctor develop an accurate diagnosis and recommend the most effective treatment for your condition.
This scan may not be available in all regions or covered by all insurance plans. Moreover, some people may not need this type of test.
Talk with your doctor to learn what types of test you need, where you can access those tests, and whether they are covered by your insurance plan if you have one.