Millions of men could benefit from faster scan to diagnose prostate cancer

A quicker, cheaper MRI scan is just as accurate at diagnosing prostate cancer as the current 30-40 minute scan and should be rolled out to make MRI scans more accessible to men who need one, according to clinical trial results led by UCLH, UCL and the University of Birmingham.

The PRIME trial, funded by the John Black Charitable Foundation and Prostate Cancer UK, and published in JAMA yesterday, confirms that a two-part MRI scan is just as effective at diagnosing prostate cancer, whilst cutting scan time to just 15-20 minutes and reducing the need for a doctor to be present.

The investigators say the results are likely to lead to changes in clinical practice, making MRI accessible to more men in the UK and beyond.

Prostate cancer is the most common cancer in men, with around 56,000 diagnoses and 12,000 deaths each year in the UK. The introduction of MRI scans over the last decade, following work by UCL and UCLH researchers, has been the biggest change in how prostate cancer is diagnosed for the past 30 years.

Abnormalities seen on the MRI scan allow targeted tissue biopsies to be taken that can improve cancer detection. A normal MRI result, which occurs in around a third of patients, is reassuring and allows men to avoid an unnecessary biopsy.

Despite the clear benefits of the MRI scan, in many healthcare settings around the world, men who need a scan still do not get one. For example, previous research has estimated that 35% of US prostate cancer patients received an MRI in 2022. In England and Wales, only 62% of men who needed a prostate MRI received one in 2019 (the most recent year for when data is available).

UCLH consultant Veeru Kasivisvanathan, the trial’s chief investigator and an associated professor at UCL, said:

“Currently around four million MRI scans are needed each year globally to diagnose prostate cancer. This demand is set to rise rapidly with a predicted surge in prostate cancer cases over the next 20 years.

“Time, cost and staff availability are all limiting factors in how many scans can be offered, which makes the results of the PRIME trial particularly important. If we can do the scan in up to half the time, with fewer staff and at lower cost, that will make a huge difference in allowing every man who needs a scan to be able to get one in a timely fashion.”

In the study, cancer specialists from 22 hospitals in 12 countries across the world recruited 555 patients aged 59-70 to see whether a streamlined two-part ‘biparametric’ MRI could detect cancer at the same rate as a full three-part ‘multiparametric’ MRI, which is currently standard of care in the UK and includes a third stage where a dye is injected into the patient.

All patients underwent the full three-part scan. Radiologists then assessed the two-part scan without the dye, and separately assessed the three-part scan with the dye, for every patient. A prostate biopsy was done when required to confirm whether or not the diagnosis was correct.

Researchers from UCL and UCLH confirmed that the two-part scan was just as effective at diagnosing prostate cancer. In total, 29% of the patients had important prostate cancer diagnosed by the shorter two-part scan, the same percentage as the longer three-part scan.

UCLH consultant radiologist Francesco Giganti, who is also an associated professor at UCL, said:

“The three-part multiparametric MRI scan has been a game-changer for the diagnosis of prostate cancer, sparing thousands of patients unnecessary biopsies and improving cancer detection.

“Currently we inject a dye into the patient that highlights the presence of cancer on the MRI scan, but this step requires time and the presence of a clinician, and can on rare occasion cause mild side effects.

“Being able to make accurate diagnoses without the contrast stage will reduce scan time meaning we can offer scans to more men using the same number of scanners and operators. However, it is vital that the scans are of optimal diagnostic quality and that they are interpreted by a radiologist with dedicated expertise in prostate MRI.”

As well as making the procedure more efficient in terms of time and personnel, a two-stage MRI would generate significant cost savings per scan. In the NHS currently, a three-phase MRI scan costs £273 on average. At £145, a two-phase scan is 47% cheaper. In countries like the US where healthcare costs tend to be much higher, the savings are likely to be even greater.

The PRIME study also received funding from the European Association of Urology Research Foundation and the Wolfgang Dieckmann Foundation.