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

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

The diagnostic accuracy and cost-effectiveness of magnetic resonance spectroscopy and enhanced magnetic resonance imaging techniques in aiding the localisation of prostate abnormalities for biopsy : a systematic review and economic evaluation

Peer reviewedPublisher PD

The primacy of multiparametric MRI in men with suspected prostate cancer

Background: Multiparametric MRI (mpMRI) became recognised in investigating those with suspected prostate cancer between 2010 and 2012; in the USA, the preventative task force moratorium on PSA screening was a strong catalyst. In a few short years, it has been adopted into daily urological and oncological practice. The pace of clinical uptake, born along by countless papers proclaiming high accuracy in detecting clinically significant prostate cancer, has sparked much debate about the timing of mpMRI within the traditional biopsy-driven clinical pathways. There are strongly held opposing views on using mpMRI as a triage test regarding the need for biopsy and/or guiding the biopsy pattern. Objective: To review the evidence base and present a position paper on the role of mpMRI in the diagnosis and management of prostate cancer. Methods: A subgroup of experts from the ESUR Prostate MRI Working Group conducted literature review and face to face and electronic exchanges to draw up a position statement. Results: This paper considers diagnostic strategies for clinically significant prostate cancer; current national and international guidance; the impact of pre-biopsy mpMRI in detection of clinically significant and clinically insignificant neoplasms; the impact of pre-biopsy mpMRI on biopsy strategies and targeting; the notion of mpMRI within a wider risk evaluation on a patient by patient basis; the problems that beset mpMRI including inter-observer variability. Conclusions: The paper concludes with a set of suggestions for using mpMRI to influence who to biopsy and who not to biopsy at diagnosis. Key Points: • Adopt mpMRI as the first, and primary, investigation in the workup of men with suspected prostate cancer. • PI-RADS assessment categories 1 and 2 have a high negative predictive value in excluding significant disease, and systematic biopsy may be postponed, especially in men with low-risk of disease following additional risk stratification. • PI-RADS assessment category lesions 4 and 5 should be targeted; PI-RADS assessment category lesion 3 may be biopsied as a target, as part of systematic biopsies or may be observed depending on risk stratification

The Influence of Transrectal Multifocal Prostate Biopsy Under Ultrasound Control on the Degree of Infravesical Obstruction in Different Groups of Patients

. Prostate cancer - is a Malignant neoplasm arising from prostatic epithelium. [1] It is well known, that prostate cancer is the most common cancer in men population. Most patients, who underwent a biopsy of prostate, have expressed varying degrees of benign prostatic hyperplasia and, accordingly, symptoms, specific to the disease, including symptoms of the lower urinary (LUTS). [2], Uroflowmetry is a method widely used around the world to assess the degree of severity of infravesical obstruction [3].The aim was to determine the degree of influence of transrectal multifocal biopsy of the prostate under ultrasound control on the degree of infravesical obstruction [4].The study included patients with elevated serum PSA over 4 ng/ml with the volume (Vpr) of prostate from 20 cm³ to 90 cm³, volume of residual urine no more than 50 cm ³. Uroflowmetry was performed with the determination of the volume of residual urine at the primary treatment. At 21 day after transrectal multifocal prostate biopsy under Ultrasound control all patients underwent uroflowmetry. The age of patients ranged from 40 to 70 years. Patients were divided into 3 groups depending on the volume of the prostate gland. The first group consisted of 28 people where prostate volume ranged from 20 cm³ to 40 cm³, in the second group, consisted of 25 persons, prostate volume ranged from 41 cm³ to 60 cm³, and in the third group, consisted of 30 people, prostate volume ranged from 61 cm³ to 90 cm³. The following indicators of urofloumetry were determined as the following: voided volume, max flow rate, average flow, voiding time, flow time, time to max flow, and the volume of residual urine.This study has demonstrated a high risk of complications in patients with prostate volume of more than 60 cm3 caused by infravesical obstruction after prostate biopsy

Non-antibiotic strategies for the prevention of infectious complications following prostate biopsy : A Systematic Review and Meta-analysis

Acknowledgments Emma Smith from the EAU Guidelines Office assisted with the systematic review, and Robert Pickard (deceased), Newcastle upon Tyne, United Kingdom, initiated this review.Peer reviewedPostprin

Does needle calibre affect pain and complication rates in patients undergoing transperineal prostate biopsy? A prospective, randomized trial

Transperineal prostate biopsy is a procedure that can be used to obtain histological samples from the prostate. To improve both the quality of the biopsy core samples and prostate cancer detection, we are currently performing a prospective, randomized trial comparing prostate biopsy samples obtained using an 18 G-needle to those obtained using a 16 G needle. The aim of this preliminary study was to evaluate pain and complication rates in both groups in order to assess whether performing a prostate biopsy with a larger calibre needle is a feasible procedure. One hundred and eighty-seven patients undergoing transperineal prostate biopsy were prospectively evaluated and divided into two groups. The first group (94 patients, Group A) received a transperineal prostate biopsy using a 16 G-needle and the second group (93 patients, Group B) underwent transperineal prostate biopsy with an 18 G-needle. Anaesthesia was obtained with a single perineal injection at the prostatic apex in all subjects. A visual analogue scale (VAS) and facial expression scale (FES) were used to assess pain during multiple steps of the procedure in each group. A detailed questionnaire was used to obtain information about drug use because it could potentially influence the pain and complications that patients experienced. Two weeks after the procedure, early and late complications were evaluated. Statistical analysis was carried out using non-parametric tests. Prostate Specific Antigen (PSA) and drug use were similar at baseline between the two groups. Pain during prostate biopsy, which was measured with both the VAS and FES instruments, did not differ significantly between the 18- and 16 G-needle groups, and no significant differences were found in early or late complication rates between the groups. Transperineal prostate biopsy with a 16 G-needle is a feasible procedure in terms of pain and complication rates. Further studies with larger patient populations are required to assess whether or not this procedure can improve prostate cancer detection rates