Prostate biopsies guided by three-dimensional real-time (4-D) transrectal ultrasonography on a phantom: comparative study versus two-dimensional transrectal ultrasound-guided biopsies

OBJECTIVE: This study evaluated the accuracy in localisation and distribution of real-time three-dimensional (4-D) ultrasound-guided biopsies on a prostate phantom. METHODS: A prostate phantom was created. A three-dimensional real-time ultrasound system with a 5.9MHz probe was used, making it possible to see several reconstructed orthogonal viewing planes in real time. Fourteen operators performed biopsies first under 2-D then 4-D transurethral ultrasound (TRUS) guidance (336 biopsies). The biopsy path was modelled using segmentation in a 3-D ultrasonographic volume. Special software was used to visualise the biopsy paths in a reference prostate and assess the sampled area. A comparative study was performed to examine the accuracy of the entry points and target of the needle. Distribution was assessed by measuring the volume sampled and a redundancy ratio of the sampled prostate. RESULTS: A significant increase in accuracy in hitting the target zone was identified using 4-D ultrasonography as compared to 2-D. There was no increase in the sampled volume or improvement in the biopsy distribution with 4-D ultrasonography as compared to 2-D. CONCLUSION: The 4-D TRUS guidance appears to show, on a synthetic model, an improvement in location accuracy and in the ability to reproduce a protocol. The biopsy distribution does not seem improved

Prosper: image and robot-guided prostate brachytherapy

Brachytherapy for localized prostate cancer consists in destroying cancer by introducing iodine radioactive seeds into the gland through hollow needles. The planning of the position of the seeds and their introduction into the prostate is based on intra-operative ultrasound (US) imaging. We propose to optimize the global quality of the procedure by: i) using 3D US; ii) enhancing US data with MRI registration; iii) using a specially designed needle-insertion robot, connected to the imaging data. The imaging methods have been successfully tested on patient data while the robot accuracy has been evaluated on a realistic deformable phantom

Development of miniaturized light endoscope-holder robot for laparoscopic surgery

PURPOSE: We have conducted experiments with an innovatively designed robot endoscope holder for laparoscopic surgery that is small and low cost. MATERIALS AND METHODS: A compact light endoscope robot (LER) that is placed on the patient's skin and can be used with the patient in the lateral or dorsal supine position was tested on cadavers and laboratory pigs in order to allow successive modifications. The current control system is based on voice recognition. The range of vision is 360 degrees with an angle of 160 degrees . Twenty-three procedures were performed. RESULTS: The tests made it possible to advance the prototype on a variety of aspects, including reliability, steadiness, ergonomics, and dimensions. The ease of installation of the robot, which takes only 5 minutes, and the easy handling made it possible for 21 of the 23 procedures to be performed without an assistant. CONCLUSION: The LER is a camera holder guided by the surgeon's voice that can eliminate the need for an assistant during laparoscopic surgery. The ease of installation and manufacture should make it an effective and inexpensive system for use on patients in the lateral and dorsal supine positions. Randomized clinical trials will soon validate a new version of this robot prior to marketing

Visual servoing of a robotic endoscope holder based on surgical instrument tracking

International audienceWe propose an image-based control for a roboticendoscope holder during laparoscopic surgery. Our aim is toprovide more comfort to the practitioner during surgery byautomatically positioning the endoscope at his request. To doso, we propose to maintain one or more instruments roughly atthe center of the laparoscopic image through different commandmodes. The originality of this method relies on the direct useof the endoscopic image and the absence of artificial markersadded to the instruments. The application is validated on a testbench with a commercial robotic endoscope holder

Biopsies prostatiques ciblées guidées par IRM dans le diagnostic du cancer de prostate (revue de la littérature et expérience clinique initiale avec l'Urostation®)

Deux axes principaux se dégagent de notre étude de la littérature : la réalisation de biopsies avec guidage direct dans l IRM, et la fusion d image échographie-IRM. Les premières offrent une grande précision, mais restent limitées par l accessibilité, le coût et la durée de ces procédures. La fusion d images est un compromis prometteur associant la précision et la spécificité de l IRM multiparamétrique, et la facilité d accès et d utilisation de l échographie endorectale. Plusieurs systèmes ont ainsi été développés, dont l Urostation®, offrant la possibilité de réaliser des biopsies ciblées à l aide d une fusion d images échographiques 3D et IRM. Nous avons inclus de manière prospective entre novembre 2011 et août 2012, 30 patients présentant une indication de biopsies prostatiques ayant réalisé une IRM multiparamétrique au CHU de Grenoble. Un protocole de 12 biopsies randomisées a été réalisé, ainsi que 2 biopsies ciblées en cas de zone suspecte. Un cancer de prostate a été diagnostiqué dans 14 cas (47%), dont 3 cancers sans anomalie IRM. Onze cancers ont été considérés cliniquement significatifs. Dans notre étude, un protocole de 2 biopsies ciblées réalisé en cas d IRM anormale avec PI-RADS score >8 aurait négligé un cancer significatif, mais évité 15 procédures inutiles et 2 cas de sur-diagnostic de cancers non significatifs, avec une sensibilité de 91% pour la détection d un cancer de prostate significatif. Des études de plus grande ampleur seront nécessaires pour définir la place de l IRM avant biopsie, des biopsies ciblées, et enfin de la fusion écho-IRM, à l heure de la robotisation, de l émergence des traitements focaux et de la réflexion sur le sur-traitement.The systematic review of the literature showed that research is focused on two main areas: direct biopsy guidance inside the MRI, and MRI-ultrasound fusion. The first offer a high precision, but are still limited by the accessibility, cost and duration of these procedures. Image fusion is a promising compromise, associating the precision and specificity of multiparametric MRI, and the accessibility and usability of transrectal ultrasound. Several systems have therefore been developped, including the Urostation®, to allow biopsy guidance based on 3D ultrasound and MRI fusion. Between November, 2011 and August, 2012, we prospectively included 30 patients presenting with an indication for prostate biopsies, who first had a multiparametric MRI in the Grenoble University Hospital. A 12-core randomised biopsy protocol was performed, as well as 2 targeted biopsies in case of suspicious lesion. Prostate cancer was detected in 14 cases (47%), including 3 cancers with MRI considered normal. Eleven cancers were considered clinically significant. In our study, a 2-core targeted biopsy protocol performed only in case of abnormal MRI with a PI-RADS score >8 would have missed one significant cancer, but avoided 15 unnecessary procedures and 2 cases of over-diagnosis of insignificant cancers, with a 91% sensitivity for the detection of significant prostate cancer. Further, larger studies are needed to define the place of MRI prior to biopsy, of targeted biopsies, and finally of MRI-ultrasound fusion, in the context of the developpement of robotics, emergence of focal therapies, and reflection on over-treatment.GRENOBLE1-BU Médecine pharm. (385162101) / SudocSudocFranceF

Développement et application préclinique du robot de curiethérapie PROSPER

Introduction : Rapporter le développement et les expérimentations d'un nouveau système robotisé destiné à la curiethérapie prostatique possédant un système de suivi de la prostate et une possibilité de fusion écho-IRM. Matériel et méthodes : Un robot d'implantation d'aiguilles transpérinéales guidé par échographie transrectale avec suivi peropératoire des mouvements et de la déformation de la prostate a été crée. Les expériences ont été conduites sur 90 cibles réalisées dans 9 fantômes conçus pour être mobiles et déformables. Les expériences ont été ensuite conduites chez 2 cadavres. Le robot a cherché à déposer des billes de verre simulant des grains de curiethérapie aussi près que possible des cibles dans des fantômes évaluables par différentes modalités d'imagerie dont le scanner et dans des prostates de cadavre. Les résultats étaient mesurés en segmentant les cibles et les billes de verre sur des volumes tomodensitométriques des fantômes et des cadavres. Résultats : Le robot était capable d'atteindre les cibles choisies dans les fantômes avec une précision médiane de 2.73 mm, avec un déplacement médian de la prostate de 5.46 mm. La précision était meilleure à la base qu'à l'apex (2.28 mm vs 3.83 mm, p<0.01) et n'était pas significativement différente pour les implantations horizontales et obliques (2.7 vs 2.82 mm, p=0.18). Les tests sur cadavre ont montré la faisabilité et l'ergonomie du robot en salle d'opération mais des expérimentations plus poussées sont nécessaires. Conclusion : Ce robot destiné à la curiethérapie prostatique est le premier système utilisant le suivi de la prostate intra-opératoire pour guider des aiguilles dans la prostate. Les expériences préliminaires montrent sa capacité à atteindre des cibles malgré les mouvements de la prostate. Les applications pourraient être élargies à la thérapie focale et aux biopsies guidées compte-tenu de sa possibilité à fusionner l'imagerie IRM et l'échographie.Purpose: To report on the development and the initial experience with a new 3D ultrasound robotic system for prostate brachytherapy assistance and focal therapy. MRI-TRUS fusion as well as its ability to track prostate motion intra-operatively allows it to manage motions and guide needles to MRI enhanced tumor foci. Materials and methods: A robotic system for TRUS-guided needle implantation combined with intraoperative prostate tracking was created. Experiments were conducted on 90 targets embedded in 9 mobile and deformable synthetic prostate phantoms. A preliminary feasibility study on 2 cadavers was also carried out. The experiments involved trying to insert glass beads as close as possible to targets in multimodal imaging phantoms and in cadaver prostates. The results were measured by segmenting the inserted beads in CT scan volumes of the phantoms and of the cadaver's radical prostatectomy specimens. Results: The robot was able to reach the chosen targets in phantoms with a median accuracy of 2.73 mm, with a median prostate motion of 5.46 mm. Accuracy was better in apex than in base (2.28 vs 3.83 mm, p<0.001) and was similar for horizontal and angled needle inclinations (2.7 vs 2.82 mm, p=0.18). Cadaver tests showed the feasibility of the robot's ergonomics in the operating room but further in vivo assessments are needed. Conclusion: This robot for prostate focal therapy and brachytherapy is the first system using intraoperative prostate motion tracking to guide needles into the prostate. The preliminary experiments described show its ability to reach targets in spite of the motion of the prostate.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Inverse Stability Problem and Applications to Renewables Integration

In modern power systems, the operating point, at which the demand and supply are balanced, may take different values due to changes in loads and renewable generation levels. Understanding the dynamics of stressed power systems with a range of operating points would be essential to assuring their reliable operation, and possibly allow higher integration of renewable resources. This letter introduces a non-traditional way to think about the stability assessment problem of power systems. Instead of estimating the set of initial states leading to a given operating condition, we characterize the set of operating conditions that a power grid converges to from a given initial state under changes in power injections and lines. We term this problem as "inverse stability," a problem which is rarely addressed in the control and systems literature, and hence, poorly understood. Exploiting quadratic approximations of the system's energy function, we introduce an estimate of the inverse stability region. Also, we briefly describe three important applications of the inverse stability notion: 1) robust stability assessment of power systems with respect to different renewable generation levels; 2) stability-constrained optimal power flow; and 3) stability-guaranteed corrective action design. ©2017 IEEE.MIT/Skoltech, Ministry of Education and Science of Russian Federation (Grant no.14.615.21.0001.)NSF (1508666)NSF (1550015

Medical image computing and computer-aided medical interventions applied to soft tissues. Work in progress in urology

Until recently, Computer-Aided Medical Interventions (CAMI) and Medical Robotics have focused on rigid and non deformable anatomical structures. Nowadays, special attention is paid to soft tissues, raising complex issues due to their mobility and deformation. Mini-invasive digestive surgery was probably one of the first fields where soft tissues were handled through the development of simulators, tracking of anatomical structures and specific assistance robots. However, other clinical domains, for instance urology, are concerned. Indeed, laparoscopic surgery, new tumour destruction techniques (e.g. HIFU, radiofrequency, or cryoablation), increasingly early detection of cancer, and use of interventional and diagnostic imaging modalities, recently opened new challenges to the urologist and scientists involved in CAMI. This resulted in the last five years in a very significant increase of research and developments of computer-aided urology systems. In this paper, we propose a description of the main problems related to computer-aided diagnostic and therapy of soft tissues and give a survey of the different types of assistance offered to the urologist: robotization, image fusion, surgical navigation. Both research projects and operational industrial systems are discussed