3-D Visualization and Inter-Session Comparison for Robotic Assisted Bladder Cancer Screening

Abstract

Over 570,000 new cases of bladder cancer are diagnosed worldwide every year[1]. It is essential to detect new tumors as early as possible to reduce the mortality rate. In addition, the muscle invasiveness of lesions should be quantified to determine the optimal treatment plan. Within the ”Next-gen in-vivo cancer diagnostics” re- search project we propose a new cystoscopy instrument consisting of an optical coherence tomography (OCT) sensor, a camera and a light source, mounted on the tip of a concentric tube robot (CTR). The camera images could then be used to create 3-D reconstructions of the bladder wall and to quantifiy changes in its texture between successive cystoscopy sessions. In addition, the camera could guide the OCT sensor to investigate the bladder wall structure at the locations of possible tumors in order to investigate the malignancy and muscle invasiveness. This research specifically reports on creating 3-D re- constructions of bladder phantoms and co-registration of successive sessions, in order to automatically detect and indicate changes in texture which might be related to the onset and growth of tumors. Several research groups performed 3-D reconstruction of the bladder based on monocular images, often in combination with a different sensor or with structured light. Lurie et al. used monocular images (2700 on average) and sophisticated algorithms to create 3-D reconstructions with sufficiently sharp textures such that thin blood vessels are made visible without interruptions [2]. Suarez-Ibarrola et al. also performed detailed 3-D reconstructions of the bladder, but an additional sensor (electromagnetic tracker or inertial measurement unit) was required [4]. Up to date no automatic detection of texture changes in successive cystoscopy sessions has been reported in literature.