#$%^&*AU2012254943A120121213.pdf#####ABSTRACT 5 A device and method for determining the effect of therapy in a tumour tissue of a human or a mammal under interstitial photodynamic or photothermal therapy by analyzing a liquid flow in a tissue of a human or a mammal. A first fibre is interstitially inserted in a first position of said tissue and connected to a light source, and a second fibre is interstitially inserted in a second position of said tissue for receiving 10 light emitted from the first fibre. A detector is arranged for receiving the light from said second fibre for producing an output signal. An analysator receives the output signal from the detector and determines if there is a frequency component in the frequency area below about 1 MHz in the output signal, which is indicative of blood cell movement in the tissue. If the frequency component is below a threshold value, it is 15 determined that there is no blood flow. In photothermal therapy, no blood flow is interpreted as the fact that the blood has coagulated and the therapy may be finalized. In photodynamic tumour therapy, changes in blood flow may be used to evaluate the treatment progression.
