Why You Might Need a PSMA PET Scan for Advanced Prostate Cancer

When you’re living with advanced prostate cancer, every new test can bring a mix of worry and hope. How might the results affect what comes next?

A PSMA PET scan can help your care team better understand if and where the cancer has spread. Radiation oncologist Rahul Tendulkar, MD, explains how this information can make a meaningful difference in the decisions you make together about your treatment.

Why did your doctor order a PSMA PET scan?

You’ve already been diagnosed and are undergoing treatment for advanced prostate cancer. So, why would your doctor order a PSMA PET scan now?

This type of scan is designed to find prostate cancer cells throughout your body — even in very small amounts. Ultimately, a PSMA PET scan helps answer one major question: Where is the cancer now? 

Dr. Tendulkar says there are two key reasons your provider might order this scan:

• Your PSA levels are rising. After radiation, surgery or hormonal therapy, your prostate-specific antigen (PSA) level usually goes down. But if it’s suddenly going up, your provider may order this scan to understand why.
• The cancer may be spreading. If your provider has reason to think that your prostate cancer may be progressing, the results of this scan can help them get a clearer picture.

“PSMA PET imaging has been able to find smaller metastases than other types of imaging, and it exposes people to much lower levels of radiation,” he adds. “It can often achieve a very high level of detection, even identifying some of the smallest lesions.”

That’s really important. Because the earlier your care team can detect recurrence, the sooner they can try to treat it.

How it’s different from other tests

In the past, providers often couldn’t detect cancer until it had grown large enough to be picked up by traditional imaging, like CT scans and bone scans. But PSMA PET scans have been shown to be 27% more accurate.

That’s because PSMA PET scans work differently. They target a specific protein found on prostate cancer cells, which causes them to “light up” on imaging. That often allows doctors to detect the return (recurrence) of prostate cancer earlier, even when PSA levels are very low.

Earlier detection can give you and your care team more options — and more time to act thoughtfully and precisely.

How the results can change your treatment

One of the biggest benefits of having a PSMA PET scan for advanced prostate cancer is that it can help pinpoint where cancer has come back or spread. And that allows your care team to better target your treatment.

Dr. Tendulkar explains that there are generally three places where prostate cancer comes back:

• Prostate region: Local recurrence is when cancer comes back to the area where it started. Even after a prostatectomy, cancer can return to the general area (called the prostate bed).
• Lymph nodes: “PSMA PET scans have been remarkably helpful at identifying early recurrences in the lymph nodes in the pelvis,” Dr. Tendulkar shares. 
• Bones: A PSMA PET scan has been shown to be more effective than a bone scan at identifying cancer that has spread to the bones.

“With a PSMA PET scan, we can provide a more accurate assessment of where the source of the cancer might be coming from,” he explains. “And if we can identify recurrence before it’s widespread, we may be able to intervene earlier.”

Importantly, the results of your PSMA PET scan allow your care team to better tailor your treatment to what’s actually happening within your body. The results guide decisions about what comes next, like:

• Whether radiation should target a specific area versus a larger region
• Whether it’s time to start, change or postpone certain treatments
• Whether you’re a candidate for specialized treatments, including PSMA-targeted therapy

“I sometimes tell people that the results of the PSMA PET scan allow us to take a ‘whac-a-mole’ approach — in a good way,” Dr. Tendulkar illustrates. “We can treat what we find now, and we can often do the same thing again in the future, if we need to. The goal is to provide long periods of being disease-free.”

What if it doesn’t find anything?

If your doctor ordered a PSMA PET scan because your PSA levels are rising, it can feel confusing and even unsettling if the results come back negative. But that information still helps your care team guide your treatment plan.

“A negative PSMA PET scan is helpful because it tells us that whatever is making your PSA rise is still microscopic at this stage,” Dr. Tendulkar explains. “That can affect how we move forward with treatment planning.”

In these cases, your doctors may recommend monitoring rather than rushing into treatment. That can help you avoid unnecessary side effects while still keeping a close eye on your health.

Questions to ask your doctor beforehand

Understanding why you need a PSMA PET scan can help give you a clearer sense of what’s to come. Consider asking questions like:

• What are you hoping to learn from this scan?
• How could the results change my treatment plan?
• If the scan finds a small number of spots, what are my options?
• What happens if the scan doesn’t show anything?
• How will this fit into my overall treatment plan moving forward?

Your care team can also help you understand what to expect during the scan itself, which usually takes fewer than two hours to complete.

Looking ahead

About 1 in 8 men will be diagnosed with prostate cancer during their lifetime — and cases of advanced prostate cancer are on the rise. But science is also evolving quickly in an effort to keep up.

“In recent years, we’ve seen really remarkable improvements in our ability to identify and treat prostate cancer,” Dr. Tendulkar reports. “PSMA PET scans are an important evolution in our ability to find recurrence at an earlier stage than ever before.”

It’s one of many tools helping healthcare providers catch recurrence earlier and tailor treatments better. And all of that, he says, offers hope for the future.

“Even if we can’t cure advanced prostate cancer up front, our goal is to turn it into a disease people can live with for a long time,” Dr. Tendulkar says. “We want you to be able to have a good, healthy quality of life going forward.”