New Quicker and Cheaper Diagnostic Trials for Prostate Cancer

Researchers are about to start a trial which, if it proves successful, could revolutionise the way prostate cancer is diagnosed.

The team from Imperial College London and Imperial College Healthcare NHS Trust will explore whether or not a new type of MRI scan can detect prostate cancer more quickly than current methods. They'll also assess if new imaging technology which helps with targeted prostate biopsies is better at detection than traditional biopsies.

If it proves effective, it's hoped the new methods will be more accurate and faster at diagnosis. The team estimates it could save the NHS £15 million a year as 1 in 8 men in the UK will be diagnosed with Prostate Cancer in their lifetime.

The work is being led by Professor Hashim Ahmed, who is chair of urology and consultant urological surgeon at Imperial College London and Imperial College Healthcare Trust. The trials have recently been awarded funding of £1 million from Cancer Research UK and Stand Up to Cancer.

Professor Ahmed says the randomised trials are linked together to try to deliver a cost-effective trial that can answer two questions.

Shorter Scans

"Normally in the UK, men who are referred by a GP with a suspicion of prostate cancer because of raised levels of PSA or a prostate nodule on rectal exam will undergo a multi-parametric MRI (mpMRI) scan which takes up to 40 minutes and includes a gadolinium contrast injection. We want to find out if a bi-parametric MRI (bpMRI) scan which is shorter, at about 15 minutes and without the contrast injection is as effective at detecting clinically significant prostate cancer," explains Ahmed.

The gadolinium helps to show the body's organs more clearly. However, there are benefits to dispensing with it.

"The gadolinium is a safe contrast agent but does have rare side effects of anaphylactic shock and allergic reaction so a doctor has to be on site when it's administered. If we don’t use gadolnium, you don't need a doctor present, which means it can be used in mobile scanners for example," says Ahmed.

He says there's also increasing evidence in literature that gadolinium gets deposited in tissue around the body; for example, in the brain in very low amounts. Although studies have not shown it causes harm, there are no longitudinal studies to prove it.

Significant Cost Savings

The bpMRI scan is shorter and cheaper explains Ahmed: "It's £100 to £150 pounds less expensive than the mpMRI scan. It also means we can increase capacity and do more scans. You are able to do twice or even three times as many scans in the same time frame, which is significant when the NHS is struggling with capacity. In the UK, we do 120,000 to 150,000 scans a year so there is potential for a large cost saving over a number of years."

"So if it proves effective, this new method could save the NHS a lot of money and allow for more men to be scanned."

Image Fusion Technology

The second aspect of the trial involves using image fusion technology for targeted biopsies. Men who have a suspicious MRI are referred for a biopsy, which involves thin needles taking small samples of tissue from the prostate to be checked for signs of cancer.

"At the moment, when you do a targeted biopsy you try to hit the area that looks suspicious on the MRI. The biopsy is guided by ultrasound imaging though so the standard approach is for the medical practitioner to look at the MRI images on one screen and then go to the patient and look at live ultrasound images. They then make a best guess as to where to take the targeted biopsies from," explains Ahmed.

"This was called cognitive fusion but is now referred to as visual registration. It requires skill but it could potentially lead to inaccuracy with areas being missed or under sampled as it relies on someone’s judgement to guide the placement of the biopsy needle," he adds.

" Over the last 5 to 7 years, there have been a number of image fusion devices which allow the MRI information to be superimposed live during the biopsy on top of the ultrasound images, in a battleship-like manner, so you can see the suspicious lesion as you've outlined it on the MRI already and you can take targeted biopsies from that. Nearly a dozen companies have developed image fusion software as they can see a big market," explains Ahmed.

There's been a mix of results from comparative studies so far. Some show no difference between visual registration and image fusion. Some show there's a difference of between 10-15% better detection of significant cancer if you use image fusion.

Professor Ahmed says: "We think the studies so far have been based in expert centres, and those operators were at the peak of their ability to do visual registration targeting. That comparison may not be fair when compared to targeted biopsies carried out across a number of different centres across the community. So, we want to find out if image fusion is more accurate than visual registration biopsies at detecting prostate cancer in a multi-centre setting."

He says the researchers need strong evidence of the potential value of image fusion for the NHS as it'll cost a lot to buy the technology for every hospital.

Large-Scale Trial

Professor Ahmed and his team want to recruit up to 3600 men to the Prostate Assessment Using Comparative Interventions – Fast MRI and Image Fusion for Cancer (PACIFIC) trial.

The team is currently submitting its documents to ethics which will take a few months then it aims to start recruiting UK wide in 20 to 30 centres.

"We will give training to make sure MRI scans and the reporting of them are standardised by experts and people doing the targeted biopsies will also get standardised training," he says.

The trial is funded for 48 months. There 'll be 36 months of recruitment and also a pilot.

Raising the Prostate Cancer Profile

Prostate cancer is the most common cancer in men. According to Prostate Cancer UK more than 47,500 men are diagnosed with prostate cancer every year. More than 11,500 men in the UK die from prostate cancer each year.

Professor Ahmed says: "I think its profile is rising. It's a male cancer and doesn’t always get talked about in general conversation. As it's a sexual organ, there may be more reticence to talk about it. I think there's also an element of male reluctance to talk about their health unfortunately. Over the last few years, I've seen that slowly change. There are a lot of conversations about breast cancer quite rightly, just not the same level of conversations about prostate cancer."

He explains: "It certainly causes slightly more total deaths every year in the UK than breast cancer. We don't have a screening programme so it's less at the forefront of healthcare commissioners and general practice. There's still an historical bias again diagnosing prostate cancer in primary care because of the old adage that men die with prostate cancer rather than from it but that can't be true as thousands of men are dying from it."

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