Prostate Interventions Research Articles

A Decade of Prostate Intervention Robots: Systematic Review

Abstract: The image-guided prostate intervention robot can assist surgeons in performing minimally invasive intervention procedures. It has the advantage of overcoming the disadvantages of a traditional surgeon's hand tremor and dependence on the need for an experienced surgeon, improving the intervention precision, and reducing the hazards caused by normal soft tissues due to surgical precision errors compared to traditional intervention procedures. In the design of prostate intervention robots, structural design, materials, actuators, and compatibility issues should be considered. Based on the above considerations, a representative literature of the last decade was selected for review. Patents and articles on image-guided prostate intervention robots published in the last 10 years (2013-2023)were searched in several electronic databases, focusing on keywords (structural design, puncture accuracy, image compatibility, actuator) for screening. We retrieved a total of 26 prostate intervention robots guided by different images, classified them by US, MRI, MRI-US and CT, selected representative robots guided by different image modalities for review and tabulated them for comparison, and finally boldly predicted that the future direction will be prostate robots guided by MRI-US images. Image-guided prostate intervention robots can improve the deficiencies of conventional intervention procedures. In the future how to improve the intervention accuracy will be the primary problem of all intervention robots, through structural design, materials, actuators, and image compatibility issues have been improved.

Prostate Artery Embolization: Mid- to Long-Term Outcomes in 1,075 Patients

PurposeTo assess the mid- to long-term safety and effectiveness of prostatic artery embolization (PAE) at a single-center cohort of 1,075 patients. Materials and MethodsThis institutional review board–approved retrospective study included patients with moderate-to-severe lower urinary tract symptoms (LUTS) or urinary retention who underwent PAE from January 2014 to July 2023. Patients were assessed at 1, 3, 6, and 12 months after PAE and yearly thereafter. The International Prostate Symptom Score (IPSS), quality of life (QoL) score, International Index of Erectile Function-5 (IIEF-5) score, prostate-specific antigen (PSA), prostate volume (PV), postvoid residual, benign prostatic obstruction (BPO) medication usage, urinary catheter status, and further prostate interventions were assessed. Adverse events were recorded and classified using the Society of Interventional Radiology (SIR) adverse events (AEs) severity classification. ResultsThe mean follow-up was 458.4 days (SD ± 559.5). The mean age was 70.4 years (SD ± 9.0), the median (interquartile range) PV was 107 g (76–150 g), and the median preprocedural IPSS, QoL, and IIEF-5 scores and PSA level were 23 (18–28), 5 (4–6), 17 (10–21), and 4.7 ng/mL (2.6–8), respectively. In the LUTS subgroup, at 1–3, 6–12, and 48–60 months, the median IPSS values were 7 (4–12, P < .001), 6 (3–11, P < .001), and 9 (4–15, P < .001), respectively. The QoL scores at the same time points were 2 (1–2, P < .001), 1 (0–2, P < .001), 2 (0–3, P < .001), respectively. Of 126 patients in the retention cohort, 119 (94%) were catheter-free at the 3-month follow-up. Ninety-patients (16% of reintervention eligible patients) required a second prostatic intervention up to 60 months after PAE. After PAE, 65.5% of patients were BPO medication–free at 1 year. Seven patients (0.65%) had severe AEs according to the SIR AE severity classification: (a) transient ischemic attacks, 3; (b) urosepsis, 2 (treated in the inpatient setting with intravenous antibiotics); and (c) prostate sloughing, 2 (needing transurethral resection of the prostate). All AEs resolved without sequelae. ConclusionsIn a large cohort with long-term longitudinal follow-up, PAE shows significant, sustained long-term relief of LUTS, improved QoL, low reintervention rate, and high BPO medication–free rates. Ninety-four percent of catheter-dependent patients at baseline were catheter-free at 3 months.

The Impact of Testosterone Therapy on Benign Prostatic Hyperplasia in Hypogonadal Men

ObjectivesTo determine the impact of testosterone therapy on the incidence of benign prostatic hyperplasia in a large cohort of hypogonadal men, and to evaluate the relationship between testosterone therapy in hypogonadal men and prostatic interventions. MethodsWe used the 2011-2020 IBM MarketScan database to identify hypogonadal males above 18 years old and determine if they received testosterone therapy. ICD-9, -10, CPT, HCPCS, and NDC codes were used for diagnoses, interventions, and medications. We ran Cox proportional hazard models to determine the effect of testosterone therapy on receiving a diagnosis of benign prostatic hyperplasia and interventions. Models were adjusted for age, region, population density, and comorbidities, with testosterone therapy within the last 6 months considered a time-varying covariate. ResultsIn our total cohort of 882,570 hypogonadal men, 157,185 (17.8%) were diagnosed with benign prostatic hyperplasia. For the first 2.5 years after hypogonadism diagnosis, there was no significant difference in the diagnosis of prostatic hyperplasia between patients on testosterone therapy and those who were not (HR:1, 95%CI:0.98-1.01, p=0.66). However, from 2.5 years onward, men who were on testosterone therapy had a 32% higher risk of receiving a diagnosis of benign prostatic hyperplasia (HR:1.32, 95%CI:1.28-1.36, p<0.001). Hypogonadal men with benign prostatic hyperplasia who received testosterone therapy showed no significant difference in interventions compared to those who did not receive testosterone (HR:0.95, 95%CI:0.89-1, p=0.08). ConclusionsIn the long term, testosterone therapy increased the risk of receiving a diagnosis of benign prostatic hyperplasia in hypogonadal men. Testosterone therapy in hypogonadal men with benign prostatic hyperplasia did not change the need for interventions.

Multimodal registration network with multi-scale feature-crossing.

A critical piece of information for prostate intervention and cancer treatment is provided by the complementary medical imaging modalities of ultrasound (US) and magnetic resonance imaging (MRI). Therefore, MRI-US image fusion is often required during prostate examination to provide contrast-enhanced TRUS, in which image registration is a key step in multimodal image fusion. We propose a novel multi-scale feature-crossing network for the prostate MRI-US image registration task. We designed a feature-crossing module to enhance information flow in the hidden layer by integrating intermediate features between adjacent scales. Additionally, an attention block utilizing three-dimensional convolution interacts information between channels, improving the correlation between different modal features. We used 100 cases randomly selected from The Cancer Imaging Archive (TCIA) for our experiments. A fivefold cross-validation method was applied, dividing the dataset into five subsets. Four subsets were used for training, and one for testing, repeating this process five times to ensure each subset served as the test set once. We test and evaluate our technique using fivefold cross-validation. The cross-validation trials result in a median target registration error of 2.20 mm on landmark centroids and a median Dice of 0.87 on prostate glands, both of which were better than the baseline model. In addition, the standard deviation of the dice similarity coefficient is 0.06, which suggests that the model is stable. We propose a novel multi-scale feature-crossing network for the prostate MRI-US image registration task. A random selection of 100 cases from The Cancer Imaging Archive (TCIA) was used to test and evaluate our approach using fivefold cross-validation. The experimental results showed that our method improves the registration accuracy. After registration, MRI and TURS images were more similar in structure and morphology, and the location and morphology of cancer were more accurately reflected in the images.

Fully Distributed Shape Sensing of a Flexible Surgical Needle Using Optical Frequency Domain Reflectometry for Prostate Interventions.

In minimally invasive procedures such as biopsies and prostate cancer brachytherapy, accurate needle placement remains challenging due to limitations in current tracking methods related to interference, reliability, resolution or image contrast. This often leads to frequent needle adjustments and reinsertions. To address these shortcomings, we introduce an optimized needle shape-sensing method using a fully distributed grating-based sensor. The proposed method uses simple trigonometric and geometric modeling of the fiber using optical frequency domain reflectometry (OFDR), without requiring prior knowledge of tissue properties or needle deflection shape and amplitude. Our optimization process includes a reproducible calibration process and a novel tip curvature compensation method. We validate our approach through experiments in artificial isotropic and inhomogeneous animal tissues, establishing ground truth using 3D stereo vision and cone beam computed tomography (CBCT) acquisitions, respectively. Our results yield an average RMSE ranging from 0.58 ± 0.21 mm to 0.66 ± 0.20 mm depending on the chosen spatial resolution, achieving the submillimeter accuracy required for interventional procedures.

Awareness and compliance of urologists in the Middle East with minimally invasive surgical devices for the management of benign prostate hyperplasia.

The objective is to assess urologists' awareness of and compliance with available minimally invasive devices (MIDs) for the management of benign prostate hyperplasia (BPH). An online Internet-based survey was sent to urologists through E-mail. Baseline characteristics included age, location and duration of practice, and number of prostatectomies performed in the previous 12 months. Awareness is based on the surgeons' opinions about their advantages and drawbacks. A total of 308 participants responded to the survey; 87.0% were most aware of Rezūm, followed by Urolift (59.1%), Aquablation (33.1%), and combined temporary implantable nitinol device (iTIND), and Zenflow (17%). In the past 12 months, 84.1% used MIDs in their practice. A total of 47.1% of respondents believe that these devices have comparable outcomes with the traditional interventions, 52.9% are unsure of their long-term benefits, and 71% feel that it is too early to judge. Forty-three percent believe that these devices are reserved only for high-risk patients, and 52% recommend that they should be available in their centers. Most respondents (90.9%) prefer Rezūm, Urolift (28.2%), and Aquablation (12.6%) because they are less invasive, less time-consuming, and have few complications. Interestingly, 59% recommend MIDs to their family members. Most respondents are more aware of Rezūm, Urolift, and Aquablation than iTIND and Zenflow. In addition, most respondents agree that these MIDs and traditional prostate interventions have comparable outcomes despite the former lacking long-term outcome assessment. High cost and no long-term data may influence the widespread acceptance of these MIDs.

Path Planning for a Prostate Intervention Robot Based on an Improved Bi-RRT Algorithm

Path Planning for a Prostate Intervention Robot Based on an Improved Bi-RRT Algorithm

Preliminary evaluation for ultrasound-guided targeted prostate biopsy using a portable surgical robot: Ex vivo results.

Robotic systems are increasingly used to enhance clinical outcomes in prostate intervention. To evaluate the clinical value of the proposed portable robot, the robot-assisted and robot-targeted punctures were validated experimentally. The robot registration utilising the electromagnetic tracker achieves coordinate transformation from the ultrasound (US) image to the robot. Subsequently, Transrectal ultrasound (TRUS)-guided phantom trials were conducted for robot-assisted, free-hand, and robot-targeted punctures. The accuracy of robot registration was 0.95mm, and the accuracy of robot-assisted, free-hand, and robot-targeted punctures was 2.38±0.64mm, 3.11±0.72mm, and 3.29±0.83mm sequentially. The registration method has been successfully applied to robot-targeted puncture. Current results indicate that the accuracy of robot-targeted puncture is slightly inferior to that of manual operations. Moreover, in manual operation, robot-assisted puncture improves the accuracy of free-hand puncture. Accuracy superior to 3.5mm demonstrates the clinical applicability of both robot-assisted and robot-targeted punctures.

Design and Validation of a Nonparasitic 2R1T Parallel Hand-Held Prostate Biopsy Robot With Remote Center of Motion

AbstractAn increasing number of grounded robots are being used in prostate interventions to improve clinical outcomes, but their large size and high-cost limit their popularity. Thus, we present a hand-held 3-degree-of-freedom (DoF) parallel robot with remote center of motion (RCM) for minimally invasive prostate biopsy applications, combining the flexibility of hand-held devices with the precision of robotic assistance. First, the kinematic structure of robotic assistance is introduced according to its design requirements. Then, the kinematic analysis of robotic assistance is carried out by using a simplified kinematic model. The kinematic parameters are designed according to the desired workspace. A prototype has been developed and validated in animal experiments. Twenty beagles of different sizes were selected for the robot-assisted and controlled experiments, resulting in target errors of 3.30 ± 1.63 mm and 5.40 ± 1.76 mm, respectively. The error of robot-assisted experiments was significantly better than in controlled experiments. Preliminary animal tests have demonstrated that the hand-held robot can improve the accuracy of free-hand biopsy punctures.

Data-driven adaptive needle insertion assist for transperineal prostate interventions

Objective. Clinical outcomes of transperineal prostate interventions, such as biopsy, thermal ablations, and brachytherapy, depend on accurate needle placement for effectiveness. However, the accurate placement of a long needle, typically 150–200 mm in length, is challenging due to needle deviation induced by needle-tissue interaction. While several approaches for needle trajectory correction have been studied, many of them do not translate well to practical applications due to the use of specialized needles not yet approved for clinical use, or to relying on needle-tissue models that need to be tailored to individual patients. Approach. In this paper, we present a robot-assisted collaborative needle insertion method that only requires an actuated passive needle guide and a conventional needle. The method is designed to assist a physician inserting a needle manually through a needle guide. If the needle is deviated from the intended path, actuators shifts the needle radially in order to steer the needle trajectory and compensate for needle deviation adaptively. The needle guide is controlled by a new data-driven algorithm which does not require a priori information about needle or tissue properties. The method was evaluated in experiments with both in vitro and ex vivo phantoms. Main results. The experiments in ex vivo tissue reported a mean final placement error of 0.36 mm with a reduction of 96.25% of placement error when compared to insertions without the use of assistive correction. Significance. Presented results show that the proposed closed-loop formulation can be successfully used to correct needle deflection during collaborative manual insertion with potential to be easily translated into clinical application.

PI-RADS 3 score: A retrospective experience of clinically significant prostate cancer detection.

The study aims to propose an optimal workflow in patients with a PI-RADS 3 (PR-3) assessment category (AC) through determining the timing and type of pathology interrogation used for the detection of clinically significant prostate cancer (csPCa) in these men based upon a 5-year retrospective review in a large academic medical center. This United States Health Insurance Probability and Accountability Act (HIPAA)-compliant, institutional review board-approved retrospective study included men without prior csPCa diagnosis who received PR-3 AC on magnetic resonance (MR) imaging (MRI). Subsequent incidence and time to csPCa diagnosis and number/type of prostate interventions was recorded. Categorical data were compared using Fisher's exact test and continuous data using ANOVA omnibus F-test. Our cohort of 3238 men identified 332 who received PR-3 as their highest AC on MRI, 240 (72.3%) of whom had pathology follow-up within 5 years. csPCa was detected in 76/240 (32%) and non-csPCa in 109/240 (45%) within 9.0 ± 10.6 months. Using a non-targeted trans-rectal ultrasound biopsy as the initial approach (n = 55), another diagnostic procedure was required to diagnose csPCa in 42/55 (76.4%) of men, compared with 3/21(14.3%) men with an initial MR targeted-biopsy approach (n = 21); (p < 0.0001). Those with csPCa had higher median serum prostate-specific antigen (PSA) and PSA density, and lower median prostate volume (p < 0.003) compared with non-csPCa/no PCa. Most patients with PR-3 AC underwent prostate pathology exams within 5 years, 32% of whom were found to have csPCa within 1 year of MRI, most often with a higher PSA density and a prior non-csPCa diagnosis. Addition of a targeted biopsy approach initially reduced the need for a second biopsy to reach a for csPCa diagnosis. Thus, a combination of systematic and targeted biopsy is advised in men with PR-3 and a co-existing abnormal PSA and PSA density.

MP13-17 INITIAL 99 CONSECUTIVE SINGLE-PORT ROBOT-ASSISTED SIMPLE PROSTATECTOMIES

You have accessJournal of UrologyCME1 Apr 2023MP13-17 INITIAL 99 CONSECUTIVE SINGLE-PORT ROBOT-ASSISTED SIMPLE PROSTATECTOMIES Roxana Ramos, Ethan Ferguson, Jaya S. Chavali, Albert Geskin, Mohamed Eltemamy, Zeyad R. Schwen, and Jihad Kaouk Roxana RamosRoxana Ramos More articles by this author , Ethan FergusonEthan Ferguson More articles by this author , Jaya S. ChavaliJaya S. Chavali More articles by this author , Albert GeskinAlbert Geskin More articles by this author , Mohamed EltemamyMohamed Eltemamy More articles by this author , Zeyad R. SchwenZeyad R. Schwen More articles by this author , and Jihad KaoukJihad Kaouk More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003233.17AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Surgical therapy for benign prostatic hyperplasia (BPH) is generally reserved for patients with severe symptoms. Single-port (SP) robot-assisted simple prostatectomy (RASP) is a novel evolving approach. Our aim is to report its advantageous outcomes. METHODS: Single-center, three-surgeon case series of 99 consecutive SP RASP from February 2019 to October 2022. The procedure consists of two main steps. Step one is to excise the obstructive adenoma up to the verumontanum. Step two consists of a 360° mucosal flap reconstruction of the bladder neck. Data were recollected prospectively and analysis was done with descriptive statistics. RESULTS: All cases were completed successfully, without the need for extra ports or conversion. A total of 97 cases were done transvesically and 2 were done through a transperitoneal approach. 45.4% and 17.1% had history of previous abdominal and prostate interventions, respectively. The most common indication was urinary retention (59.5%). Median estimated blood loss was 100 ml and median operative time was 185 min. Most of the patients (76.7%) were discharged within 24 hours, with a median pain score of 2.5. Median length of stay was 5.6 hours in planned outpatient cases. Upon discharge, 77.8% of patients did not need narcotics. The median duration of Foley catheter was 5 days. The preoperative median IPSS, maximum flow rate, and PVR were 21, 6 ml/sec, and 156.5 ml, respectively. All of which improved through time (Figure 1). Readmission rate was 0%. CONCLUSIONS: SP RASP is a feasible procedure that includes reconstruction of the mucosal flap after excision of the adenoma. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e179 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Roxana Ramos More articles by this author Ethan Ferguson More articles by this author Jaya S. Chavali More articles by this author Albert Geskin More articles by this author Mohamed Eltemamy More articles by this author Zeyad R. Schwen More articles by this author Jihad Kaouk More articles by this author Expand All Advertisement PDF downloadLoading ...

MR conditional prostate intervention systems and actuations review.

Magnetic resonance imaging (MRI) has the ability to provide high-resolution images of soft tissues without the use of radiation. So much research has been focused on the development of actuators and robotic devices that can be used in the MRI environment so "real-time" images can be obtained during surgeries. With real-time guidance from MRI, robots can perform surgical procedures with high accuracy and through less invasive routes. This technique can also significantly reduce the operation time and simplify pre-surgical procedures. Therefore, research on robot-assisted MRI-guided prostate intervention has attracted a great deal of interest, and several successful clinical trials have been published in recent years, pointing to the great potential of this technology. However, the development of MRI-guided robots is still in the primary stage, and collaboration between researchers and commercial suppliers is still needed to improve such robot systems. This review presents an overview of MRI-guided prostate intervention devices and actuators. Additionally, the expected technical challenges and future advances in this field are discussed.

Automatic segmentation of prostate and extracapsular structures in MRI to predict needle deflection in percutaneous prostate intervention.

Understanding the three-dimensional anatomy of percutaneous intervention in prostate cancer is essential to avoid complications. Recently, attempts have been made to use machine learning to automate the segmentation of functional structures such as the prostate gland, rectum, and bladder. However, a paucity of material is available to segment extracapsular structures that are known to cause needle deflection during percutaneous interventions. This research aims to explore the feasibility of the automatic segmentation of prostate and extracapsular structures to predict needle deflection. Using pelvic magnetic resonance imagings (MRIs), 3D U-Net was trained and optimized for the prostate and extracapsular structures (bladder, rectum, pubic bone, pelvic diaphragm muscle, bulbospongiosus muscle, bull of the penis, ischiocavernosus muscle, crus of the penis, transverse perineal muscle, obturator internus muscle, and seminal vesicle). The segmentation accuracy was validated by putting intra-procedural MRIs into the 3D U-Net to segment the prostate and extracapsular structures in the image. Then, the segmented structures were used to predict deflected needle path in in-bore MRI-guided biopsy using a model-based approach. The 3D U-Net yielded Dice scores to parenchymal organs (0.61-0.83), such as prostate, bladder, rectum, bulb of the penis, crus of the penis, but lower in muscle structures (0.03-0.31), except and obturator internus muscle (0.71). The 3D U-Net showed higher Dice scores for functional structures ([Formula: see text]0.001) and complication-related structures ([Formula: see text]0.001). The segmentation of extracapsular anatomies helped to predict the deflected needle path in MRI-guided prostate interventions of the prostate with the accuracy of 0.9 to 4.9 mm. Our segmentation method using 3D U-Net provided an accurate anatomical understanding of the prostate and extracapsular structures. In addition, our method was suitable for segmenting functional and complication-related structures. Finally, 3D images of the prostate and extracapsular structures could simulate the needle pathway to predict needle deflections.

Design and evaluation of an MRI-ready, self-propelled needle for prostate interventions.

Prostate cancer diagnosis and focal laser ablation treatment both require the insertion of a needle for biopsy and optical fibre positioning. Needle insertion in soft tissues may cause tissue motion and deformation, which can, in turn, result in tissue damage and needle positioning errors. In this study, we present a prototype system making use of a wasp-inspired (bioinspired) self-propelled needle, which is able to move forward with zero external push force, thereby avoiding large tissue motion and deformation. Additionally, the actuation system solely consists of 3D printed parts and is therefore safe to use inside a magnetic resonance imaging (MRI) system. The needle consists of six parallel 0.25-mm diameter Nitinol rods driven by the actuation system. In the prototype, the self-propelled motion is achieved by advancing one needle segment while retracting the others. The advancing needle segment has to overcome a cutting and friction force while the retracting needle segments experience a friction force in the opposite direction. The needle self-propels through the tissue when the friction force of the five retracting needle segments overcomes the sum of the friction and cutting forces of the advancing needle segment. We tested the performance of the prototype in ex vivo human prostate tissue inside a preclinical MRI system in terms of the slip ratio of the needle with respect to the prostate tissue. The results showed that the needle was visible in MR images and that the needle was able to self-propel through the tissue with a slip ratio in the range of 0.78-0.95. The prototype is a step toward self-propelled needles for MRI-guided transperineal laser ablation as a method to treat prostate cancer.

Cooperative Brachytherapy Robotic Concept for Localized Cancer Treatment Under Real-Time MRI

Currently, localized cancer treatment is one of the focused research interests of Physicians. Indeed, with the advent of sensor and actuator technologies with the feasibility of integrating multiple systems, treatment and diagnosis have gained more interest in incorporating Magnetic Resonance Imaging (MRI) due to better soft-tissue contrast. In this paper, the authors report the development of the MR-based Cooperative Brachytherapy (CoBra) robot design for in-bore patient prostate intervention, in terms of diagnosis and treatment of localized cancers. The presented CoBra system is characterized by three main MR-compatible components: a suitable leg-support ensuring patient stabilization, a versatile robotized needle guide, and an automated implant driver to deposit precisely radioactive seeds. In fact, ergonomically in-bore needle placement is a challenging problem, whereas the CoBra robot aims to help in in-bore intra-operative intervention under closed-loop control based on imagery feedback. This feedback might be exploited judiciously for tracking online the biological target during changes after needle insertions. Within this framework, the paper discusses the CoBra robot with a focus on kinematics design, modeling, instrumentation, control, and MRI in-bore robot tests, with respect to the adopted clinical workflow. Also, Preliminary experimental results simulating an adaptive prostate LDR-BT under 3 Tesla MRI are given to validate the proposed concept.

Kinematic and mechanical modelling of a novel 4-DOF robotic needle guide for MRI-guided prostate intervention

Traditionally ultrasound-guided biopsy has been used to diagnose prostate cancer despite of its poor soft tissue contrast and frequent false negative results. Magnetic Resonance Imaging (MRI) has the advantage of excellent soft tissue contrast for guiding and monitoring prostate biopsy. However, its working area and access in the confined MRI bore space limit the use of interventional guide devices including robotic systems. To provide robotic precision, greater access, and compact design, we designed a novel robotic mechanism that can provide four degrees of freedom (DOF) manipulation in a compact form comparable to size of manual templates. To develop the mechanism, we established a mathematical model of inverse and forward kinematics and prototyped a proof-of-concept needle guide for MRI guided prostate biopsy. The mechanism was materialized using four discs that house small passive spherical joints that can be moved by rotating the discs consisting of grooved profile. With an initial needle insertion angle range of ±15⁰, we identified mathematical and kinematic parameters for the mechanism design and fabricated the first prototype that has dimension of 40 × 110 × 180 mm3. The prototype demonstrated that the unique robotic manipulation can physically be delivered and could provide precise needle guidance including angulated needle insertion with higher structural rigidity.

A novel registration-based algorithm for prostate segmentation via the combination of SSM and CNN.

Precise determination of target is an essential procedure in prostate interventions, such as prostate biopsy, lesion detection, and targeted therapy. However, the prostate delineation may be tough in some cases due to tissue ambiguity or lack of partial anatomical boundary. In this study, we propose a novel supervised registration-based algorithm for precise prostate segmentation, which combines the convolutional neural network (CNN) with a statistical shape model (SSM). The proposed network mainly consists of two branches. One called SSM-Net branch was exploited to predict the shape transform matrix, shape control parameters, and shape fine-tuning vector, for the generation of the prostate boundary. Furthermore, according to the inferred boundary, a normalized distance map was calculated as the output of SSM-Net. Another branch named ResU-Net was employed to predict a probability label map from the input images at the same time. Integrating the output of these two branches, the optimal weighted sum of the distance map and the probability map was regarded as the prostatesegmentation. Two public data sets PROMISE12 and NCI-ISBI 2013 were utilized to evaluate the performance of the proposed algorithm. The results demonstrated that the segmentation algorithm achieved the best performance with an SSM of 9500 nodes, which obtained a dice of 0.907 and an average surface distance of 1.85 mm. Compared with other methods, our algorithm delineates the prostate region more accurately and efficiently. In addition, we verified the impact of model elasticity augmentation and the fine-tuning item on the network segmentation capability. As a result, both factors have improved the delineation accuracy, with dice increased by 10% and 7%,respectively. Our segmentation method has the potential to be an effective and robust approach for prostatesegmentation.

Image quality assessment for machine learning tasks using meta-reinforcement learning.

In this paper, we consider image quality assessment (IQA) as a measure of how images are amenable with respect to a given downstream task, or task amenability. When the task is performed using machine learning algorithms, such as a neural-network-based task predictor for image classification or segmentation, the performance of the task predictor provides an objective estimate of task amenability. In this work, we use an IQA controller to predict the task amenability which, itself being parameterised by neural networks, can be trained simultaneously with the task predictor. We further develop a meta-reinforcement learning framework to improve the adaptability for both IQA controllers and task predictors, such that they can be fine-tuned efficiently on new datasets or meta-tasks. We demonstrate the efficacy of the proposed task-specific, adaptable IQA approach, using two clinical applications for ultrasound-guided prostate intervention and pneumonia detection on X-ray images.

Real-Time MRI-Guided Prostate Interventions.

Simple SummaryMagnetic resonance imaging has shown to be a reliable imaging method for detecting clinically significant prostate cancer and directly targeting lesions during biopsy. As newer treatment methods emerge, the role of MRI in minimally-invasive (focal) treatment of prostate cancer is also increasing. Here, we review the real-time MRI-guided prostate interventions for prostate cancer diagnosis and treatment, focusing on the technical aspects of each modality.Prostate cancer (PCa) is the second most common cause of cancer death in males. Targeting MRI-visible lesions has led to an overall increase in the detection of clinically significant PCa compared to the prior practice of random ultrasound-guided biopsy of the prostate. Additionally, advances in MRI-guided minimally invasive focal treatments are providing new options for patients with PCa. This review summarizes the currently utilized real-time MRI-guided interventions for PCa diagnosis and treatment.