A team from the University of Arkansas for Medical Sciences (UAMS) has developed a non-invasive tool which not only detects circulating tumor cells (CTCs) in the bloodstream, but can blast them away at the same time. Dubbed the Cytophone, it employs a laser which heats the CTCs, subsequently detecting them via ultrasound before turning up the heat again to kill them.

CTCs are the means by which metastasis (secondary malignant growths) occurs, so detecting and responding to them quickly is key to halting – or at least inhibiting – the spread of cancer. This isn't the first time lasers have been used by researchers to detect cancer, nor to attack it, but this – according to the the team – is the first demonstration of a non-invasive method of detecting CTCs directly in the bloodstream of melanoma patients.

But the Cytophone is more than just a detection device, it can blast these cells as well. In the detection phase, the laser penetrates the blood vessel, heating the dark melanin nanoparticles in the CTCs. Because they heat more quickly than surrounding particles, the rapid thermal expansion of these nanoparticles generates a unique sound which is detected via an ultrasound transducer on the skin surface. To destroy the CTCs, the laser further heats them, creating nano bubbles which eventually destroy the tumor cell. This hunter/killer capability means that the Cytophone has the potential to act as a dual therapeutic and diagnostic (theranostic) tool.