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

Real-time Prostate Motion Tracking For Robot-assisted Laparoscopic Radical Prostatectomy

Radical prostatectomy surgery (RP) is the gold standard for treatment of localized prostate cancer (PCa). Recently, emergence of minimally invasive techniques such as Laparoscopic Radical Prostatectomy (LRP) and Robot-Assisted Laparoscopic Radical Prostatectomy (RARP) has improved the outcomes for prostatectomy. However, it remains difficult for surgeons to make informed decisions regarding resection margins and nerve sparing since the location of the tumour within the organ is not usually visible in a laparoscopic view. While MRI enables visualization of the salient structures and cancer foci, its efficacy in LRP is reduced unless it is fused into a stereoscopic view such that homologous structures overlap. Registration of the MRI image and peri-operative ultrasound image either via visual manual alignment or using a fully automated registration can potentially be exploited to bring the pre-operative information into alignment with the patient coordinate system at the beginning of the procedure. While doing so, prostate motion needs to be compensated in real-time to synchronize the stereoscopic view with the pre-operative MRI during the prostatectomy procedure. In this thesis, two tracking methods are proposed to assess prostate rigid rotation and translation for the prostatectomy. The first method presents a 2D-to-3D point-to-line registration algorithm to measure prostate motion and translation with respect to an initial 3D TRUS image. The second method investigates a point-based stereoscopic tracking technique to compensate for rigid prostate motion so that the same motion can be applied to the pre-operative images

Arc-to-line frame registration method for ultrasound and photoacoustic image-guided intraoperative robot-assisted laparoscopic prostatectomy

Purpose: To achieve effective robot-assisted laparoscopic prostatectomy, the integration of transrectal ultrasound (TRUS) imaging system which is the most widely used imaging modelity in prostate imaging is essential. However, manual manipulation of the ultrasound transducer during the procedure will significantly interfere with the surgery. Therefore, we propose an image co-registration algorithm based on a photoacoustic marker method, where the ultrasound / photoacoustic (US/PA) images can be registered to the endoscopic camera images to ultimately enable the TRUS transducer to automatically track the surgical instrument Methods: An optimization-based algorithm is proposed to co-register the images from the two different imaging modalities. The principles of light propagation and an uncertainty in PM detection were assumed in this algorithm to improve the stability and accuracy of the algorithm. The algorithm is validated using the previously developed US/PA image-guided system with a da Vinci surgical robot. Results: The target-registration-error (TRE) is measured to evaluate the proposed algorithm. In both simulation and experimental demonstration, the proposed algorithm achieved a sub-centimeter accuracy which is acceptable in practical clinics. The result is also comparable with our previous approach, and the proposed method can be implemented with a normal white light stereo camera and doesn't require highly accurate localization of the PM. Conclusion: The proposed frame registration algorithm enabled a simple yet efficient integration of commercial US/PA imaging system into laparoscopic surgical setting by leveraging the characteristic properties of acoustic wave propagation and laser excitation, contributing to automated US/PA image-guided surgical intervention applications.Comment: 12 pages, 9 figure

Organisation of Prostate Cancer Services in the English National Health Service.

AIMS: The National Prostate Cancer Audit (NPCA) started in April 2013 with the aim of assessing the process of care and its outcomes in men diagnosed with prostate cancer in England and Wales. One of the key aims of the audit was to assess the configuration and availability of specialist prostate cancer services in England. MATERIALS AND METHODS: In 2014, the NPCA undertook an organisational survey of all 143 acute National Health Service (NHS) Trusts and 48 specialist multidisciplinary team (MDT) hubs cross England. Questionnaires established the availability and location of core diagnostic, treatment and patient-centred support services for the management of non-metastatic prostate cancer in addition to specific diagnostic and treatment procedures that reflect the continuing evolution of prostate cancer management, such as high-intensity focused ultrasound (HIFU) and stereotactic body radiotherapy. RESULTS: The survey received a 100% response rate. The results showed considerable geographical variation with respect to the availability of core treatment modalities, the size of the target population and catchment areas served by specialist MDT hubs, as well as in the uptake of additional procedures and services. Specifically there are gaps in the availability of core radiotherapy procedures; high dose rate and low dose rate brachytherapy are available in 44% and 75% of specialist MDTs, respectively. By comparison, there seems to be a relative 'over-penetration' of surgical innovation, with 67% of specialist MDTs providing robotic-assisted laparoscopic prostatectomy and 21% HIFU. There is also evidence of increased centralisation of core surgical procedures and regional inequity in the availability of surgical innovation across England. CONCLUSIONS: The organisational survey of the NPCA has provided a comprehensive assessment of the structure and function of specialist MDTs in England and the availability of prostate cancer procedures and services. As part of the prospective audit, the NPCA will assess the effect of the availability of prostate cancer services on access regionally and subsequent outcomes of care according to evidence-based guidelines

Image Guided Robots for Urology

This dissertation addresses the development of medical image-guided robots and their applications in urology. Image-guided robots integrate medical image information with robotic precision to assist the planning and execution of the image-guided interventions. Robots guided by two different image modalities, ultrasound and MR image, were developed. Ultrasound image-guided robots manipulate an ultrasound probe and a needle-guide that are calibrated with respect to the robot for image-guided targeting. A method for calibration was developed and verified through the image-guided targeting experiments. Robotic manipulation of the calibrated probe allows acquisition of image slices at precise location, which can be combined to generate a 3D ultrasound image. Software for 3D ultrasound image acquisition, processing, and segmentation was developed as a part of the image-guided robot system. The feasibility of several image-guided intervention procedures using the ultrasound image-guided robot system was tested. The robot was used in a clinical trial of intraoperative transrectal ultrasound (TRUS) guided prostatectomy. The accuracy of TRUS-guided prostate biopsy using the robot was evaluated in a comparative study versus the classic human operation of the probe. Robot controlled palpation and image processing methods were developed for ultrasound elastography imaging of the prostate. An ultrasound to CT image-fusion method using the robot as a common reference was developed for percutaneous access of the kidney. MRI-guided robots were developed for transrectal and transperineal prostate biopsy. Extensive in-vitro tests were performed to ensure MRI compatibility and image-guided accuracy of the robots. The transrectal robot was evaluated in an animal study and the transperineal robot is undergoing a clinical trial. The collection of methods and algorithms presented in this dissertation can contribute to the development of image-guided robots that may provide less invasive and more precise interventions in urology, interventional radiology, and other fields

Medical Robotics

The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

Computer- and robot-assisted Medical Intervention

Medical robotics includes assistive devices used by the physician in order to make his/her diagnostic or therapeutic practices easier and more efficient. This chapter focuses on such systems. It introduces the general field of Computer-Assisted Medical Interventions, its aims, its different components and describes the place of robots in that context. The evolutions in terms of general design and control paradigms in the development of medical robots are presented and issues specific to that application domain are discussed. A view of existing systems, on-going developments and future trends is given. A case-study is detailed. Other types of robotic help in the medical environment (such as for assisting a handicapped person, for rehabilitation of a patient or for replacement of some damaged/suppressed limbs or organs) are out of the scope of this chapter.Comment: Handbook of Automation, Shimon Nof (Ed.) (2009) 000-00

Anesthetic considerations for robot-assisted gynecologic and urology surgery

Robotic surgery was first conceived by the United States military in the 1980s. It rapidly developed in both complexity and utility and, in the early 21st century, modern robotic surgery for gynecologic and urologic surgery gained approval in the United States. Today, an ever-increasing number and variety of surgical procedures enlist robotic-assistance. Numerous anesthetic considerations for robotic surgery exist. A few of the most important aspects of conducting a safe anesthetic include: investigating the patient’s co-morbid conditions, realizing the risks associated with the robotic equipment, and positioning the patient with care. This manuscript reviews the current literature on robotic-assisted surgery for gynecologic and urologic procedures with emphasis on history, marketplace, type, variety, and expansion of surgery in these fields. The review focuses on practical considerations for the anesthesiologist caring for patients undergoing robotic surgery. Preoperative, intraoperative and postoperative issues are explored in detail. The rapid expansion of robotic surgery worldwide requires thoughtful consideration of the technique’s weaknesses and associated risks. This review provides a roadmap to adequately prepare anesthesiologists for care of gynecologic and urologic patients undergoing robot-assisted surgery