Innovative research by Imperial College London has found a new type of ultrasound scan that can diagnose prostate cancer.
An ultrasound scan is a procedure that uses high-frequency sound waves to create an image of part of the inside of the body. It is a common scan that is often used to monitor an unborn baby or diagnose conditions.
Researchers at Imperial College London, University of College London and Imperial College Healthcare NHS Trust have discovered a new type of ultrasound scan that can diagnose most prostate cancer cases with good accuracy. There is currently no single, conclusive test for prostate cancer. Therefore, advancements in assessment options for this condition is crucial.
The study was published in Lancet Oncology.
New ultrasound scan technology
Finding new ways to diagnose prostate cancer that are cost-effective, and time-saving is essential. MRI scans are often used in the diagnosis process; however, this method is expensive. The research team believe that an ultrasound scan should be used as the first test in a community healthcare setting. It also has potential for use in low-and-middle-income countries which do not have easy access to high-quality MRI scans.
Professor Hashim Ahmed, lead author of the study and Chair of Urology at Imperial College London, said: “Prostate cancer is the most commonly diagnosed cancer in the UK. One in six men will be diagnosed with the disease in their lifetimes and that figure is expected to rise.
“Our study is the first to show that a special type of ultrasound scan can be used as a potential test to detect clinically significant cases of prostate cancer. They can detect most cases of prostate cancer with good accuracy, although MRI scans are slightly better.
The new study analysed the use of a different kind of ultrasound scan technology called multiparametric ultrasound (mpUSS), which uses soundwaves to look at the prostate. The test involves a probe called a transducer to make the images of the prostate and is placed in the rectum. Following this, it sends waves that bounce off the organs and other structures. These are made into pictures of the organs.
Furthermore, the doctor completing the test uses an extra special type of ultrasound scan imaging that looks at the stiffness of the tissue and the amount of blood supply the tissue has. These are called elastography, doppler and contrast-enhancement with microbubbles. As cancers are denser and have a greater blood supply, they show up more clearly.
This new ultrasound scan technology is more widely available than the standard MRI; however, no large-scale studies validate its effectiveness as a test to detect prostate cancer cases.
Clinical trial
The new trial, known as cancer diagnosis by multiparametric ultrasound of the prostate (CADMUS), recruited 370 men at risk of prostate cancer. They were identified following initial tests such as a prostate-specific antigen (PSA) test and/or an abnormal digital rectal examination that examines a person’s lower rectum, pelvis and lower belly.
Taking place at seven hospitals across the UK, the trial was carried out between March 2016-November 2019.
The men were given both the new ultrasound scan, mpUSS and mpMRI scans at separate visits, followed by biopsies which use thin needles to take small samples of tissue from the prostate cancer to analyse under a microscope for cancer. Cancer was detected in 133 men, with a further 83 men diagnosed with clinically significant cancer. Individually, the new ultrasound scan technology – mpUSS – detected 66 cases of clinically significant cancer compared to mpMRI, which detected 77 cases.
Although mpUSS detected 4.3% fewer clinically important prostate cancers compared to the mpMRI, the researchers said this method would lead to 11.1% more patients being biopsied. This was because the mpUSS sometimes showed up in abnormal areas even though there was no cancer.
The researchers outlined that this ultrasound scan could be used as an alternative to mpMRI as a first test for patients at risk of prostate cancer, particularly in situations where a mpMRI cannot be carried out. Both imaging tests missed clinically-important cancers detected by the other, so using both would increase the detection of clinically important prostate cancers compared to using each test alone.
