A multi-parametric magnetic resonance imaging (mpMRI) scan is a special type of scan that creates more detailed pictures of your prostate than a standard MRI scan. It does this by combining up to four different types of image. These images give your doctor information about whether or not there is any cancer inside your prostate, and how quickly any cancer is likely to grow.
If you’ve just been diagnosed with prostate cancer, you may have a standard MRI scan to find out if the cancer has spread outside your prostate. This helps your doctor to work out the most suitable treatment options for you.
But research has now shown that it may be more useful to do an mpMRI scan than a standard scan, and to do it at an earlier stage – before you have a prostate biopsy.
There are two main ways that an mpMRI scan may be useful before a biopsy.
- It can help your doctor decide if you need a prostate biopsy.
- If you do need a biopsy, it should be possible to use the scans to make the biopsy more accurate.
Helping to decide if you need a biopsy
A large new study has shown that an mpMRI scan can accurately show whether there is anything unusual in the prostate, or the area around it, that might be cancer. If there’s anything unusual on the scan, you’ll be offered a prostate biopsy to find out whether you have cancer.
Importantly, an mpMRI scan is less likely than a biopsy to pick up a slow-growing or non-aggressive cancer that probably wouldn’t cause any symptoms or problems in your lifetime. It usually only picks up areas of faster-growing cancer that do need treating. If you have a slow-growing cancer, it’s less likely to show up on the scan. So if your scan is clear, you’re unlikely to have prostate cancer that needs to be treated, and your doctor might decide that you don’t need to have a biopsy. This means you’d avoid the possible side effects of a biopsy. And you’d avoid being diagnosed with a slow-growing cancer and possibly having treatment that you didn’t need.
Making prostate biopsies more accurate
An mpMRI scan may still be useful, even if you do need to have a biopsy. This is because the doctor may be able to use the scans to decide which areas of the prostate to take samples from. This is known as a targeted biopsy.
If you haven’t had an mpMRI scan, the doctor will usually use a thin needle to take 10 to 12 small pieces of tissue from different areas of the prostate. But if you’ve had an mpMRI scan, they may just put the biopsy needle into the areas of the prostate that look unusual on the scan. This means they’re more likely to find the cancer, if there is any. It also means they may be able to use fewer needles and take fewer pieces of tissue from the prostate.
Some doctors might decide to do both a targeted biopsy and the usual 10 to 12 sample biopsy. Your doctor will discuss this with you.
Other possible benefits
Another possible advantage of having an mpMRI scan before a biopsy is that, if the biopsy finds cancer, you probably won’t need another MRI scan to find out if your cancer has spread. Your doctor can probably look at your previous scan results to find this out. This means you and your doctor can start discussing suitable treatment options as soon as you get your biopsy results.
Doing an MRI scan before your biopsy, rather than after, means the images are clearer and your doctor will have a better idea about whether or not your cancer has spread. This is because biopsies cause bleeding and swelling in the prostate that can make the MRI less clear. If you haven’t already had an MRI scan, you’ll usually have to wait four to six weeks after your biopsy before having one. Some men feel anxious waiting for a scan to find out if their cancer has spread.
Will I have an mpMRI scan before a biopsy?
Research showing the benefits of doing an mpMRI scan before a biopsy has only recently been published (January 2017). Some hospitals have already started doing an mpMRI scan before deciding whether to do a biopsy. But mpMRI scans before biopsy aren’t available in all hospitals. If you’re having tests for prostate cancer, ask your doctor about having an mpMRI scan. If your hospital doesn’t do mpMRI scans before biopsy, your doctor may be able to refer you to one that does.
If none of the hospitals in your local area do mpMRI scans before biopsy, and your doctor recommends having a prostate biopsy, this can still help to find prostate cancer. Read more about having a prostate biopsy.
Last updated: December 2016
To be reviewed: December 2018