A team of researchers from Scotland, Canada and the Netherlands have reached a significant new milestone in optical monitoring for medical applications. The team have employed an advanced infrared detector, based on a superconducting nanowire. This allowed them to measure the signature of an excited (‘singlet-state’) form of oxygen that is generated during photodynamic therapy and results in tumor cell death in this emerging method of cancer treatment. Nathan Gemmell, the PhD research student who performed the experiments at Heriot-Watt University, says, "the exceptional performance of our superconducting detector allowed us to make measurements for the first time using an optical fibre to pick up the light from the decay of the excited oxygen molecules." Professor Brian Wilson of the Ontario Cancer Institute adds that "the ability to perform these measurements is a marked step forward for this field. The flexibility to use an optical fibre is a tremendous practical advantage and in future will allow dose monitoring to be performed locally within tumors, opening the possibility for accurate ‘on line’ control to ensure the highest tumor kill without damaging normal healthy tissues."

The results are published in Optics Express.

Source: Robert Hadfield