Optoacoustic imaging of an animal model of prostate cancer

Abstract

Prostate cancer is currently the most common cancer among Canadian men. Due to an increase in public awareness and screening, prostate cancer is being detected at earlier stages and in much younger men. This is raising the need for better treatment monitoring approaches. Optoacoustic imaging is a new technique that involves exposing tissues to pulsed light and detecting the acoustic waves generated by the tissue. Optoacoustic images of a tumour bearing mouse and an agematched control were acquired for a 775 nm illumination using a reverse-mode imaging system. A murine model of prostate cancer, TRAMP (transgenetic adenocarcinoma of mouse prostate), was investigated. The results show an increase in optoacoustic signal generated by the tumour compared to that generated by the surrounding tissues with a contrast ratio of 3.5. The dimensions of the tumour in the optoacoustic image agreed with the true tumour dimensions to within 0.5 mm. In this study we show that there are detectable changes in optoacoustic signal strength that arise from the presence of a tumour in the prostate, which demonstrates the potential of optoacoustic imaging for the monitoring of prostate cancer therapy.