3D scan is the smart way to target tiny prostate tumours
APIONEERING two in one scanning system can detect prostate cancer as accurately as experts visually examining MRI scans, according to research.
A study in the journal european Urology compared the new SmartTarget system with the standard technique — in which doctors mentally estimate the location of the tumour using MRI (magnetic resonance imaging).
It found that both techniques separately picked up 80 cases of cancer that could pose a risk, according to University College London Hospital, which tested both on 129 patients with suspected prostate cancer.
But each technique also found 13 cancers the other missed — suggesting a combination, using both SmartTarget and the doctor’s visual analysis of the scans, would give the best results for patients.
If the methods had been combined in this study, they would have detected 93 tumours.
experts hailed the results of the study, in December 2018, as demonstrating that SmartTarget effectively pinpoints suspicious areas, allowing doctors to perform highly accurate biopsies — and, if cancer is present, to treat it more precisely.
Professor Hashim Ahmed, chair of urology at Imperial College London, says the accuracy of SmartTarget allows doctors to identify prostate cancer more rapidly.
‘This means patients can access the right treatment early enough,’ he adds. Professor Ahmed was involved in the SmartTarget trial, which was funded by the Department of Health and Social Care and the Wellcome Health Innovation Challenge Fund.
‘Prostate cancer detection has been improving at a very fast rate. This technology pushes the science even further forward.
‘Its accuracy means it could reduce the number of biopsies needed and cut down on unnecessary operations caused by overdiagnosis of less harmful cancers.
‘Because it’s relatively easy to use, SmartTarget could also enable less experienced centres to catch up with others on their diagnosis rates.’
This is because staff who don’t have the necessary skills can be trained quickly to use SmartTarget, enabling centres to improve their prostate cancer detection rates. Tim Dudderidge, a consultant urological surgeon from University Hospital Southampton, says: ‘ Targeting tumours can be difficult, but the evidence shows this system makes that much easier and reliable. Fewer biopsies can be taken — and SmartTarget is userfriendly.’
With more than 46,000 new cases a year, prostate cancer is the most common cancer in British men.
A biopsy of the prostate, a walnutsized gland underneath the bladder, can confirm the disease — but ultrasound scans used to decide which pieces of the prostate to sample can be unclear, leaving the doctor effectively working blind.
As a result, half of lifethreatening cancers are missed and healthy tissue can be removed, which sometimes leads to impotence. Ultrasound biopsies can also be painful and invasive, especially if the doctor has to take several samples.
THE SmartTarget system — developed at University College London — provides detailed images, allowing the doctor to home in quickly on suspect areas. It is already being used in hospitals and combines detailed prebiopsy MRI scans with realtime ultrasound images, providing unprecedented views.
‘It’s like a fighter pilot getting images from an augmented reality cockpit display,’ says Professor Mark emberton, an honorary consultant at University College London Hospitals NHS Foundation Trust, who has been involved in the development of SmartTarget.
SmartTarget first uses multiparametric MRI, which combines three types of MRI scan, to produce highly detailed images of the prostate.
It is more sensitive than traditional MRI in detecting small tumours that could nonetheless be very dangerous.
SmartTarget software then uses the scan to create a 3D onscreen model, where abnormal tissue shows as yellow.
When the biopsy begins, an ultrasound is done as usual, and these ‘ live’ images are
superimposed on to the model. This lets the doctor quickly and easily find areas of concern.
Without the latest technology, a doctor couldn’t simultaneously perform a biopsy and MRI scan — because the patient would be inside the scanner.
So, traditionally, the MRI is done before the biopsy — the doctor then analyses the images, calculates the area to target, and, during the biopsy, refers back to the MRI image.
As this requires six months’ training and practice, some hospitals lack staff with the necessary skills. Ultrasound scanning with a probe is comparatively straightforward.
With the dual scanning system, crucial details are also provided, such as the size, shape and exact position of the tumour within the prostate, which an ultrasound alone would not provide, nor in such detail using a traditional MRI.
And, unlike with ultrasound or standard MRI, the biopsy is carried out through the skin in the area between the patient’s testicles and back passage, rather than the usual route through the back passage, as it is more targeted.
Cancer detected can then be destroyed using highintensity focused ultrasound (HIFU), a relatively new, but very accurate, technique using ultrasonic waves to heat up cancer cells and kill them without destroying healthy tissue.
The SmartTarget model can be adjusted to accommodate the patient moving, ensuring greater accuracy during biopsy and treatment.
Retired surveyor David Beale, 70, underwent SmartTarget as part of a trial. He was diagnosed with prostate cancer in 2010 after complaining to his GP of bladder infections, a common symptom. Doctors suggested delaying treatment, because a traditional biopsy suggested his was a slowgrowing cancer. They continued to monitor him with blood tests, an approach known as ‘watchful waiting’.
However, over the years, these tests revealed that his levels of PSA (prostatespecific antigen protein), made by the prostate and potentially indicating cancer, were increasing.
In 2016, David joined the SmartTarget study, which revealed some of his cancer was fastergrowing. The same year, he joined another trial, where patients were given an injection of artificially created bacteria, PRX302, to activate PSA to target and destroy the cancer.
‘This reduced my tumour to a level where it was unlikely to kill me — unfortunately, though, the improvement was only temporary,’ says David.
By 2018, his PSA reading was ten; ten or above is considered high risk, so his doctors used SmartTarget with HIFU to locate and destroy the tumour. His PSA is now stable at around seven — considered normal for a healthy man of his age.
David says: ‘I’ve got a caravan in Wales and I can now drive all the way there from Halesowen in the West Midlands without needing to stop for the loo.’