Detection Of Positive Cancer Margins Intra-operatively During Nephrectomy And Prostatectomy Using Optical Reflectance Spectroscopy

In recent years optical spectroscopies have become the basis for popular research activity directed towards the development of novel, noninvasive technologies for tissue diagnostics. The motivation for my research was to eliminate the need for surgical removal of tissue samples for biopsy and histology. With the help of an optical probe placed on or near the surface of the tissue, Near Infrared (NIR) spectroscopy can provide diagnostic signatures, non-invasively and in real time. While the ultimate goal vi is the elimination of the need to remove tissue samples, this technology can also be used to provide additional guidance during laparoscopic surgery. In this study, optical reflectance spectroscopy with short source-detector separation is used as a minimally invasive technique to differentiate normal tissues from tumor lesions ex-vivo. Reflectance spectra (340nm -1035nm) were acquired with an optical probe, from human specimens after radical or partial nephrectomys and prostatectomy. The main aim was to differentiate between normal and tumor tissues and then extend the application to differentiate between benign and malignant tissues. The study involved 13 human subjects for prostate measurements and 23 human subjects for kidney measurements. For kidney tissue, promising parameters were the slope of the reflectance spectrum from 630nm to 900nm, correlation coefficients between the normal and tumor (benign and malignant) reflectance spectrums from 560nm to 630nm and two-wavelength classifications. For prostate tissue, promising parameters were the slope of the reflectance spectrum from 630nm to 900nm. Reflectance spectroscopy can be further used with an optical probe having large source detector separation to image deep inside the tissues. A "smart" probe can be designed which can be used intra-operatively to provide real time surgical guidance during laparoscopic surgery.