3D Biopsy: A New Method to Diagnose Prostate Cancer

Abstract

Transperineal mapping biopsy (TPMB) is a substantial improvement over transrectal ultrasound guided biopsy (TRUS) in accurate grading and lesion identification, yet lacks standardization and in its current form utilizes antiquated technology. Theoretical models demonstrate that sampling the prostate at 5 mm intervals with a 15-gauge biopsy needle would detect 2.5 mm lesions with excellent accuracy. In practice, this approach is problematic due to deflection of biopsy needles during travel into the gland, movement of the gland during respiration, and technological constraints requiring multiple sampling attempts along the same needle path to cover the full length of the prostate. To help solve these problems, a software program was created to provide a real-time 3D image of the prostate generated from intraoperative axial (transverse) image capture. This software both generates a biopsy plan designed to provide complete coverage of the gland and subsequently monitors sampling in real-time to ensure adequate coverage is obtained. Moreover, if a patient is found to have cancer amenable to targeted focal therapy, the 3D map can be utilized in the OR to locate the sites to be ablated. What follows is a detailed description of how the software works and what additional changes are necessary to overcome the current challenges facing TPMB. The increased sampling accuracy that can be obtained with 3D mapping biopsy (MB) is necessary for proper risk stratification allowing improved selection of surveillance candidates.