New MRI scan could detect prostate cancer in minutes

By Stephen Beech

Millions of men could benefit from a new, faster prostate cancer scan.

The quicker, cheaper MRI scan was just as accurate at diagnosing prostate cancer in clinical trials as the current 30- to 40-minute scan.

It should be rolled out to make MRI scans more accessible to men who need one, say scientists.

The PRIME trial confirms that a two-part MRI scan is just as effective at diagnosing prostate cancer, while cutting scan time to just 15 to 20 minutes and reducing the need for a doctor to be present.

The research team, led by University College London (UCL) and University of Birmingham scientists, say the results are likely to lead to changes in clinical practice, making MRI accessible to more men in the UK and elsewhere.

Prostate cancer is the most common form of the disease 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 has been the biggest change in how prostate cancer is diagnosed in the last 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.

But, 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.

Lead researcher Associate Professor Veeru Kasivisvanathan, of 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.”

Cancer specialists from 22 hospitals in 12 countries recruited 555 patients aged 59 to 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, then radiologists 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 confirmed that the two-part scan was just as effective at diagnosing prostate cancer.

Almost three out of 10 patients (29%) had important prostate cancer diagnosed by the shorter two-part scan - the same percentage as the longer three-part scan, according to the findings published in the Journal of the American Medical Association (JAMA).

UCL Associate Professor Francesco Giganti 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, researchers say two-stage MRI would generate "significant" cost savings per scan.

In the NHS currently, a three-phase MRI scan costs an average of £273. At £145, a two-phase scan is 47% cheaper.

In countries including the United States, where healthcare costs tend to be much higher, the savings are likely to be even greater.

Prostate Cancer UK’s Transform trial, the biggest prostate cancer screening trial for 20 years that will include MRI, is due to begin later this year.

The trial is to find the best way to screen men for prostate cancer, achieving the evidence needed for the introduction of a national screening programme.

Scientists say the results of the PRIME trial are an important step towards realising this ambition.

Dr. Matthew Hobbs, director of research at Prostate Cancer UK, said: “The results from the PRIME trial, showing that a faster, cheaper, type of prostate MRI is just as good as the current standard MRI at detecting prostate cancer, are a hugely important step in the right direction for making MRIs more efficient.

“Another trial is already happening in the UK and the results of the two trials together should provide the complete evidence package we need to change practice across the country.

"We encourage NICE to prepare to review their guidelines as soon as that evidence base is complete, so that we can make MRI quicker, cheaper and less onerous for men."

He added: "Our funding for PRIME, alongside the John Black Charitable Foundation, also provided recommendations of a few simple ways for hospitals to improve scan quality.

"So, while we await a review by NICE, hospitals should use guidelines from UCL's GLIMPSE trial, so that they are ready for the implementation of biparametric MRI if it's recommended, and so that the men having MRI scans right now get the most accurate scan possible.”