Optical spectroscopy and imaging using near-infrared light provide powerful tools for non-invasive screening and clinical detection of diseased tissues located on surface, subsurface and even in the areas of deep organs. This chapter reviews and provides a noninvasive optical imaging technique for detecting and 3D-locating cancerous sites in prostate from viewing through the rectum. It presents an optical imaging using independent component analysis (OPTICA)-based inverse image reconstruction algorithm specifically for the application of backscattering configuration. The 3D locations of small piece of Cytate-stained cancerous prostate tissue hidden inside the large host normal prostate tissue were used to verify our new OPTICA algorithm by sets of 2D backscattering images recorded by our specifically developed prostatoscope analyzer scanning imaging unit. The algorithm of OPTICA is based on that ICA of the perturbations in the spatial intensity distributions provides the corresponding independent intensity distributions on the detector planes.