Advances in bi-modal optical and ultrasound detection of prostate cancer diagnosis

摘要

Prostate cancer diagnosis is based on PSA dosage and digital rectal examination. In case of positive test, a biopsy is conducted and guided by ultrasound imaging. Today, however, as ultrasound imaging is not able to precisely detect tumors, some biopsies have to be performed in the prostate and the only way to improve detection is to increase the number of those uncomfortable biopsies. In order to decrease this number and to improve the patient wellness, we are studying a way to couple ultrasound and fluorescence optical imaging on an endorectal probe. The ultrasounds are used to get morphological information on the prostate and the optical system to detect and to localize fluorophore marked tumors. To support the development of such a system, we have carried out a new tissue-mimicking phantom which represents the three different kind of tissue concerned during prostate endorectal examination: prostate, rectum, surrounding tissues. It was imaged by ultrasound and by fluorescence diffuse optical imaging. We have proved that the optical system is able to detect and to localize a fluorescing inclusion at different depth inside the phantom which has then been superimposed to the morphological image provided by the ultrasounds.