Virtual Reality Navigation System for Prostate Biopsy

Prostate cancer is the most common non-cutaneous cancer in America. The detection of prostate cancer involves non-invasive early screening tests, but positive results in the tests have to be confirmed undergoing a prostate biopsy which is the most accurate way to evaluate the presence of cancerous cells inside the prostate gland. The standard biopsy procedure is a blind systematic procedure in which samples are taken from different regions of the prostate under the guidance of a TRUS. In the last years some methods of TRUS-MRI fusion biopsy have been introduced in order to use the MRI to target the suspicious areas. It has been proved that targeted biopsy can improved the detection rate and reduce the risks due to the oversampling of the prostate. Despites those advantages, the target biopsy is not widespread because the high complexity and costs of the image fusion system. This thesis project achieved the implementation of the virtual reality navigation system for prostate biopsy (VRPBx), an innovative approach for targeted prostate biopsy. The system, conceived, developed and evaluate with the help of expert urology surgeons, is described in all its software/hardware components. In the proposed navigation system the traditional TRUS guidance has been successfully replaced by an EMTS to constantly track the position of the needle in the operating environment. A sensor, the needle sensor, is placed on the biopsy needle in order to have real- time information on its location. A second sensor, the correction sensor, placed on the patient pelvis, tracks the position of the patient pelvis. Some fiducial markers are positioned on the patient pelvis while the MRI is acquired, and then during a process of registration the position of these markers is measured by the EMTS. Fusing the information on the markers position in the two coordinate systems, the registration is achieved and virtual images helps the surgeon performing a targeted biopsy.