The diagnosis and treatment of prostate cancer could be improved with a tactile ‘e-finger’ device that measures mechanical tumour properties.
The first planned prototype will be a glove incorporating sensors, hopefully followed by an entirely autonomous robotic probe at some stage in the future.
Researchers from Heriot-Watt University have received a £400,000 grant from the EPSRC (Engineering and Physical Sciences Research Council) to develop the technology, after demonstrating the basic principles in the lab.
They experimented on prostate biopsies — both malignant and benign — performing mechanical tests on the tissue with a specialised hydraulic-rig setup. Crucially, the results showed that mechanical output correlated strongly with the biochemical signals that underpin cancer development.
‘One of our key innovations is that we’re making a measurement of dynamic mechanical properties, as opposed to static mechanical properties,’ said project lead Prof Bob Reuben of Heriot-Watt.
‘The palpation isn’t just press once and get the force-displacement curve; it’s essentially a vibratory measurement and out of that we get a dynamic modulus that varies with frequency — so, potentially, there’s more information in that than you would get in a single elastic modulus.’
The technique allows mesoscale mechanical measurements — that is, at the level of tissue — as well as micro- and nanoscale measurements at the level of cell groups or individual cells. The latter also has the potential to build up a three-dimensional ‘mechanical map’ of the tumour.
The challenge for the team now will be transferring this knowledge into a device that can work on living tissue, in vivo.
‘We expect the relationships will be even stronger in living tissue, but we have to demonstrate that of course and there are a whole lot of issues around deployment of the probe, ensuring we can make the measurement in the face of tissue movement and all those kinds of things,’ Reuben said. The first planned device will be a low-cost glove that can be used by general practitioners.
‘If we can instrument what doctors feel when they do a digital rectal examination, if you can record that, it’s a much stronger diagnosis than when it’s an impression — a bit like recording what you can hear down a stethoscope,’ Reuben said.
He stressed that the test would be used in conjunction with other techniques, such as ultrasound, but could in theory negate the need for invasive biopsy and help in the treatment-planning process.
It could also be used further down the line by surgeons testing the so-called ‘resection margins’ where the tumour is removed to ensure that no cancerous tissue remains.