Research from Imperial College London and University College London has found that a new type of ultrasound scan can diagnose most prostate cancer cases
In a clinical trial involving 370 men, the ultrasound scans missed just 4.3 per cent of clinically important prostate cases, cancer that should be treated rather than monitored in comparison to magnetic resonance imaging (MRI) scans. MRI scans are currently used to detect prostate cancer.
The study took place at seven hospitals in the UK including lead site Charing Cross Hospital, part of Imperial College Healthcare NHS Trust, between March 2016 to November 2019.
The study looked at the use of imaging called multiparametric ultrasound (mpUSS), which uses soundwaves to look at the prostate. The test involves the use of a probe called a transducer to make the images of the prostate. It is placed into the rectum and sends out sound waves that bounce off organs and other structures. These are then made into pictures of the organs.
The doctor doing the test also uses extra special types of ultrasound imaging that look at how stiff the tissue is and how much blood supply 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.
The men were given both mpUSS and mpMRI scans at separate visits. This was then followed by biopsies – which involves using thin needles to take small samples of tissue from the prostate to analyse under a microscope to check cancer – for 257 patients who had a positive mpUSS or mpMRI test result. The team then compared the results from the tests.
Cancer was detected in 133 men, with 83 men diagnosed with clinically significant cancer. Although mpUSS detected 4.3 per cent fewer clinically-important prostate cancers compared to mpMRI the researchers said this method would lead to 11.1 per cent more patients being biopsied. This was because the mpUSS sometimes showed up in abnormal areas even though there was no cancer.
Prostate cancer MRI scans
Some of the issues with MRI scans are that they are expensive and time-consuming. The researchers believe that an ultrasound scan should be used as the first test in a community healthcare setting. It could also be a good solution for low and middle-income countries which do not have easy access to high-quality MRI scans. It could be used in combination with current MRI scans to increase the chances of cancer detection.
Professor Hashim Ahmed, 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.
“MRI scans are one of the tests we use to diagnose prostate cancer. Although effective these scans are expensive, take up to 40 minutes to perform and are not easily available to all. Also, there are some patients who are unable to have MRI scans such as those with hip replacements or claustrophobia fears.
As cancer waiting lists build as a result of the COVID-19 pandemic, there is a real need to find more efficient and cheaper tests to diagnose prostate cancer. 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.”
Prostate cancer detection
Prostate cancer is one of the most common cancer in men in the UK with approximately 52,300 new cases diagnosed each year. Cancer develops when cells in the prostate grow in an uncontrolled way. Prostate cancer develops slowly and symptoms such as the blood in the urine do not appear until the disease has developed.
One of the main methods to diagnose prostate cancer is a special type of magnetic resonance imaging (MRI) scan called a multi-parametric MRI (mpMRI) scan, which helps doctors see if there is any cancer inside the prostate and how quickly the cancer is likely to grow. However, the scan takes 40 minutes and costs up to £450.
The researchers believe that the test can be used as an alternative to mpMRI as the first test for patients at risk of prostate cancer, in particular where mpMRI tests 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 on its own.
Dr Alistair Grey, UCL Division of Surgery & Interventional Science, said: “Our results provide an accurate test for prostate cancer in patients who were previously without one using a scan that’s cheap and easy to conduct.”
