title: Ex vivo study of prostate cancer localization using rolling mechanical imaging towards minimally invasive surgery.
abstract: Rolling mechanical imaging (RMI) is a novel technique towards the detection and quantification of malignant tissue in locations that are inaccessible to palpation during robotic minimally invasive surgery (MIS); the approach is shown to achieve results of higher precision than is possible using the human hand. Using a passive robotic manipulator, a lightweight and force sensitive wheeled probe is driven across the surface of tissue samples to collect continuous measurements of wheel-tissue dynamics. A color-coded map is then generated to visualize the stiffness distribution within the internal tissue structure. Having developed the RMI device in-house, we aim to compare the accuracy of this technique to commonly used methods of localizing prostate cancer in current practice: digital rectal exam (DRE), magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS) biopsy. Final histology is the gold standard used for comparison. A total of 126 sites from 21 robotic-assisted radical prostatectomy specimens were examined. Analysis was performed for sensitivity, specificity, accuracy, and predictive value across all patient risk profiles (defined by PSA, Gleason score and pathological score). Of all techniques, pre-operative biopsy had the highest sensitivity (76.2%) and accuracy (64.3%) in the localization of tumor in the final specimen. However, RMI had a higher sensitivity (44.4%) and accuracy (57.9%) than both DRE (38.1% and 52.4%, respectively) and MRI (33.3% and 57.9%, respectively). These findings suggest a role for RMI towards MIS, where haptic feedback is lacking. While our approach has focused on urological tumors, RMI has potential applicability to other extirpative oncological procedures and to diagnostics (e.g., breast cancer screening).
authors.affiliation: Department of Informatics, Centre for Robotics Research, King's College London, London WC2R 2LS, UK; School of Engineering and Computing Sciences, Durham University, Durham DH1 3LE, UK; School of Electrical and Electronic Engineering, Newcastle University, Newcastle-Upon-Tyne NE1 7RU, UK. Electronic address: jichun.li@newcastle.ac.uk.
authors.forename: Jichun
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Informatics, Centre for Robotics Research, King's College London, London WC2R 2LS, UK.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Urology, Guy's and St. Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Brown
authors.affiliation: Department of Urology, Guy's and St. Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK; MRC Centre for Transplantation, NIHR Biomedical Research Centre, King's Health Partners, Guy's Hospital, London SE1 9RT, UK.
authors.forename: Pardeep
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Urology, Guy's and St. Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK; MRC Centre for Transplantation, NIHR Biomedical Research Centre, King's Health Partners, Guy's Hospital, London SE1 9RT, UK.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Challacombe
authors.affiliation: Department of Histopathology, Guy's and St. Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK.
authors.forename: Ashish
authors.initials: A
authors.lastname: Chandra
authors.affiliation: Department of Radiology, Guy's and St. Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK.
authors.forename: Giles
authors.initials: G
authors.lastname: Rottenberg
authors.affiliation: Department of Informatics, Centre for Robotics Research, King's College London, London WC2R 2LS, UK; Khalifa University Robotics Institute, Khalifa University, Abu Dhabi, United Arab Emirates.
authors.forename: Lakmal D
authors.initials: LD
authors.lastname: Seneviratne
authors.affiliation: Department of Informatics, Centre for Robotics Research, King's College London, London WC2R 2LS, UK; Centre for Advanced Robotics @ Queen Mary (ARQ), Faculty of Science and Engineering, Queen Mary University of London, London E1 4NS, UK.
authors.forename: Kaspar
authors.initials: K
authors.lastname: Althoefer
authors.affiliation: Department of Urology, Guy's and St. Thomas' Hospital NHS Foundation Trust, London SE1 9RT, UK; MRC Centre for Transplantation, NIHR Biomedical Research Centre, King's Health Partners, Guy's Hospital, London SE1 9RT, UK.
authors.forename: Prokar
authors.initials: P
authors.lastname: Dasgupta
mesh_terms: D001696:Biomechanical Phenomena; D001706:Biopsy; D051517:Digital Rectal Examination; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D055595:Mechanical Phenomena; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D014463:Ultrasonography
keywords: Robotic minimally invasive surgery; Rolling mechanical imaging; Wheeled probe