MR Guided Prostate Biopsy

We perform transperineal MRI-guided biopsies for prostate cancer at the wide-bore 3T MRI scanner in AMIGO. The wide-bore 3T MRI (Siemens), combined with custom built software and hardware, was made possible through NIH grants, enabling us to launch this unique and clinically useful program from the inception of the AMIGO suite. Men with either recurrent prostate cancer post-surgeries or radiation treatments, or with consecutive negative ultrasound-guided biopsies but rising PSA are enrolled in our program.

In addition, we have recently begun a new clinical research program to investigate the feasibility of focal ablation therapies for prostate cancer using MRI-guidance. Extending the software, hardware, and multi-parametric MRI methods developed in MRI-guided biopsies, we perform cryoablation of the dominant lesion to manage cancer recurrence following treatments. In the patients who have been successfully treated so far, the advantage of planning, targeting, and guidance under wide bore 3T MRI in AMIGO has been demonstrated. The wide bore scanner allows patients to remain in the scanner during the placement of the cryoablation probe under MRI guidance. By keeping the patients statically in the scanner, a detailed ablation plan, produced at the beginning of the procedure, can be overlaid onto the intra-procedural images without image registration, a significant advantage over other potential approaches in which the patient would be moved into the scanner for imaging, then out of the scanner for ablation probe placement.

Prostate Biopsy Workflow in AMIGO

Preprocedural planning. The radiologist reviews the preprocedural multi-parametric MRI exams to identify suspicious targets.
Patient preparation. White Arrows: Custom-made MR imaging-compatible table top with leg support. Black Arrow: Template with holes for the accurate biopsy needle placement is placed against the patient's perineum.
Patient preparation. The patient is taken to the 70 cm wide-bore 3T MRI and placed on the prostate intervention table in the lithotomy position. The sterile stationary frame and the template with the Z-frame are set up.
Patient preparation. View of the template with the Z- shaped calibration frame (Z-frame).
Intraoperative MRI. A 2D slice image of the Z-frame for the Z-frame registration is taken. The 3D view of the model of the Z-frame and the template overlaid on the slice image is displayed on the navigation software (3D Slicer).
Intraoperative MRI. A second intraprocedural 2D multi-slice T2-weighted (T2W) image is obtained. For the registration, the region of interest is marked through manual cropping, so that afterwards, the two images become joined.
Intraoperative Planning. Through projection of all the intraprocedural and preprocedural targets onto the intraprocedural T2W image, 3D Slicer selects the optimal template holes for biopsy needle insertion and the depth for the needles. On the 3D view, the optimal needle path is calculated, (Green = Needle Path, Red = Target, Blue = Template, Yellow = Z-Frame).
Needle Placement. Following the Z-frame detachment from the template, the radiologist applies local anesthetic and inserts an 18-gauge × 15 cm MRI-compatible core biopsy needle through the selected hole until it reaches the calculated insertion depth.
Monitoring. Upon needle insertion, a 2D needle confirmation image is obtained in either the axial or the coronal plane at the planned target position to confirm that the needle was placed at the desired position. The needle placement was confirmed by the artifact shown on the real-time image. If the needle is not found sufficiently close to the target lesion, the needle is reinserted through a selected hole based on MR image guidance. Upon satisfactory placement of the needle tip over the target (based on the MR), the tissue samples are collected, labeled, and sent for site-specific pathological examination.

 

 

Software

SliceTracker is a 3D Slicer extension designed to support the workflow of the in-bore MRI-guided targeted prostate biopsy (MRgBx) (see references below for clinical context). This extension was developed and tested to support transperineal MRgBx procedure in the Advanced Multimodality Image Guided Operating (AMIGO)."

 

Book Chapters

Robert A. Cormack. Image-Guided Prostate Brachytherapy. Ch.57. Part V. mage-Guided Clinical Applications. In Ferenc A. Jolesz (Ed.), Intraoperative Imaging and Image-Guided Therapy. New York, NY: Springer; 2014. pp. 761-70.

Select Publications

Herz C, MacNeil K, Behringer PA, Tokuda J, Mehrtash A, Mousavi P, Kikinis R, Fennessy FM, Tempany CM, Tuncali K, et al. Open Source Platform for Transperineal In-Bore MRI-Guided Targeted Prostate Biopsy. IEEE Trans Biomed Eng. 2020;67 (2) :565-76.Abstract
OBJECTIVE: Accurate biopsy sampling of the suspected lesions is critical for the diagnosis and clinical management of prostate cancer. Transperineal in-bore MRI-guided prostate biopsy (tpMRgBx) is a targeted biopsy technique that was shown to be safe, efficient, and accurate. Our goal was to develop an open source software platform to support evaluation, refinement, and translation of this biopsy approach. METHODS: We developed SliceTracker, a 3D Slicer extension to support tpMRgBx. We followed modular design of the implementation to enable customization of the interface and interchange of image segmentation and registration components to assess their effect on the processing time, precision, and accuracy of the biopsy needle placement. The platform and supporting documentation were developed to enable the use of software by an operator with minimal technical training to facilitate translation. Retrospective evaluation studied registration accuracy, effect of the prostate segmentation approach, and re-identification time of biopsy targets. Prospective evaluation focused on the total procedure time and biopsy targeting error (BTE). RESULTS: Evaluation utilized data from 73 retrospective and ten prospective tpMRgBx cases. Mean landmark registration error for retrospective evaluation was 1.88 ± 2.63 mm, and was not sensitive to the approach used for prostate gland segmentation. Prospectively, we observed target re-identification time of 4.60 ± 2.40 min and BTE of 2.40 ± 0.98 mm. CONCLUSION: SliceTracker is modular and extensible open source platform for supporting image processing aspects of the tpMRgBx procedure. It has been successfully utilized to support clinical research procedures at our site.
Patel NA, Li G, Shang W, Wartenberg M, Heffter T, Burdette EC, Iordachita I, Tokuda J, Hata N, Tempany CM, et al. System Integration and Preliminary Clinical Evaluation of a Robotic System for MRI-Guided Transperineal Prostate Biopsy. J Med Robot Res. 2019;4 (2).Abstract
This paper presents the development, preclinical evaluation, and preliminary clinical study of a robotic system for targeted transperineal prostate biopsy under direct interventional magnetic resonance imaging (MRI) guidance. The clinically integrated robotic system is developed based on a modular design approach, comprised of surgical navigation application, robot control software, MRI robot controller hardware, and robotic needle placement manipulator. The system provides enabling technologies for MRI-guided procedures. It can be easily transported and setup for supporting the clinical workflow of interventional procedures, and the system is readily extensible and reconfigurable to other clinical applications. Preclinical evaluation of the system is performed with phantom studies in a 3 Tesla MRI scanner, rehearsing the proposed clinical workflow, and demonstrating an in-plane targeting error of 1.5mm. The robotic system has been approved by the institutional review board (IRB) for clinical trials. A preliminary clinical study is conducted with the patient consent, demonstrating the targeting errors at two biopsy target sites to be 4.0 and 3.7, which is sufficient to target a clinically significant tumor foci. First-in-human trials to evaluate the system's effectiveness and accuracy for MR image-guide prostate biopsy are underway.
Mehrtash A, Ghafoorian M, Pernelle G, Ziaei A, Heslinga FG, Tuncali K, Fedorov A, Kikinis R, Tempany CM, Wells WM, et al. Automatic Needle Segmentation and Localization in MRI with 3D Convolutional Neural Networks: Application to MRI-targeted Prostate Biopsy. IEEE Trans Med Imaging. 2019;38 (4) :1026-36.Abstract
Image-guidance improves tissue sampling during biopsy by allowing the physician to visualize the tip and trajectory of the biopsy needle relative to the target in MRI, CT, ultrasound, or other relevant imagery. This paper reports a system for fast automatic needle tip and trajectory localization and visualization in MRI that has been developed and tested in the context of an active clinical research program in prostate biopsy. To the best of our knowledge, this is the first reported system for this clinical application, and also the first reported system that leverages deep neural networks for segmentation and localization of needles in MRI across biomedical applications. Needle tip and trajectory were annotated on 583 T2-weighted intra-procedural MRI scans acquired after needle insertion for 71 patients who underwent transperenial MRI-targeted biopsy procedure at our institution. The images were divided into two independent training-validation and test sets at the patient level. A deep 3-dimensional fully convolutional neural network model was developed, trained and deployed on these samples. The accuracy of the proposed method, as tested on previously unseen data, was 2.80 mm average in needle tip detection, and 0.98° in needle trajectory angle. An observer study was designed in which independent annotations by a second observer, blinded to the original observer, were compared to the output of the proposed method. The resultant error was comparable to the measured inter-observer concordance, reinforcing the clinical acceptability of the proposed method. The proposed system has the potential for deployment in clinical routine.
Moreira P, Patel N, Wartenberg M, Li G, Tuncali K, Heffter T, Burdette EC, Iordachita I, Fischer GS, Hata N, et al. Evaluation of Robot-assisted MRI-guided Prostate Biopsy: Needle Path Analysis during Clinical Trials. Phys Med Biol. 2018;63 (20) :20NT02.Abstract
PURPOSE: While the interaction between a needle and the surrounding tissue is known to cause a significant targeting error in prostate biopsy leading to false-negative results, few studies have demonstrated how it impacts in the actual procedure. We performed a pilot study on robot-assisted MRI-guided prostate biopsy with an emphasis on the in-depth analysis of the needle-tissue interaction in-vivo. Methods: The data were acquired during in-bore transperineal prostate biopsies in patients using a 4 degrees-of-freedom (DoF) MRI-compatible robot. The anatomical structures in the pelvic area and the needle path were reconstructed from MR images, and quantitatively analyzed. We analyzed each structure individually and also proposed a mathematical model to investigate the influence of those structures in the targeting error using the mixed-model regression. Results: The median targeting error in 188 insertions (27 patients) was 6.3mm. Both the individual anatomical structure analysis and the mixed-model analysis showed that the deviation resulted from the contact between the needle and the skin as the main source of error. On contrary, needle bending inside the tissue (expressed as needle curvature) did not vary among insertions with targeting errors above and below the average. The analysis indicated that insertions crossing the bulbospongiosus presented a targeting error lower than the average. The mixed-model analysis demonstrated that the distance between the needle guide and the patient skin, the deviation at the entry point, and the path length inside the pelvic diaphragm had a statistically significant contribution to the targeting error (p<0.05). Conclusions: Our results indicate that the errors associated with the elastic contact between the needle and the skin were more prominent than the needle bending along the insertion. Our findings will help to improve the preoperative planning of transperineal prostate biopsies.
Verma S, Choyke PL, Eberhardt SC, Oto A, Tempany CM, Turkbey B, Rosenkrantz AB. The Current State of MR Imaging-targeted Biopsy Techniques for Detection of Prostate Cancer. Radiology. 2017;285 (2) :343-56.Abstract
Systematic transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations because of its inability to accurately visualize and target prostate lesions. Multiparametric magnetic resonance (MR) imaging of the prostate is more reliably able to localize significant prostate cancer. Targeted prostate biopsy by using MR imaging may thus help to reduce false-negative results and improve risk assessment. Several commercial devices are now available for targeted prostate biopsy, including in-gantry MR imaging-targeted biopsy and real-time transrectal US-MR imaging fusion biopsy systems. This article reviews the current status of MR imaging-targeted biopsy platforms, including technical considerations, as well as advantages and challenges of each technique.
Glazer DI, Mayo-Smith WW, Sainani NI, Sadow CA, Vangel MG, Tempany CM, Dunne RM. Interreader Agreement of Prostate Imaging Reporting and Data System Version 2 Using an In-Bore MRI-Guided Prostate Biopsy Cohort: A Single Institution's Initial Experience. AJR Am J Roentgenol. 2017;209 (3) :W145-51.Abstract
OBJECTIVE: The purpose of this study is to determine the interobserver agreement of the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for diagnosing prostate cancer using in-bore MRI-guided prostate biopsy as the reference standard. MATERIALS AND METHODS: Fifty-nine patients underwent in-bore MRI-guided prostate biopsy between January 21, 2010, and August 21, 2013, and underwent diagnostic multiparametric MRI 6 months or less before biopsy. A single index lesion per patient was selected after retrospective review of MR images. Three fellowship-trained abdominal radiologists (with 1-11 years' experience) blinded to clinical information interpreted all studies according to PI-RADSv2. Interobserver agreement was assessed using Cohen kappa statistics. RESULTS: Thirty-eight lesions were in the peripheral zone and 21 were in the transition zone. Cancer was diagnosed in 26 patients (44%). Overall PI-RADS scores were higher for all biopsy-positive lesions (mean ± SD, 3.9 ± 1.1) than for biopsy-negative lesions (3.1 ± 1.0; p < 0.0001) and for clinically significant lesions (4.2 ± 1.0) than for clinically insignificant lesions (3.1 ± 1.0; p < 0.0001). Overall suspicion score interobserver agreement was moderate (κ = 0.45). There was moderate interobserver agreement among overall PI-RADS scores in the peripheral zone (κ = 0.46) and fair agreement in the transition zone (κ = 0.36). CONCLUSION: PI-RADSv2 scores were higher in the biopsy-positive group. PI-RADSv2 showed moderate interobserver agreement among abdominal radiologists with no prior experience using the scoring system.
Velez E, Fedorov A, Tuncali K, Olubiyi O, Allard CB, Kibel AS, Tempany CM. Pathologic Correlation of Transperineal In-Bore 3-Tesla Magnetic Resonance Imaging-Guided Prostate Biopsy Samples with Radical Prostatectomy Specimen. Abdom Radiol (NY). 2017;42 (8) :2154-9.Abstract

PURPOSE: To determine the accuracy of in-bore transperineal 3-Tesla (T) magnetic resonance (MR) imaging-guided prostate biopsies for predicting final Gleason grades in patients who subsequently underwent radical prostatectomy (RP). METHODS: A retrospective review of men who underwent transperineal MR imaging-guided prostate biopsy (tpMRGB) with subsequent radical prostatectomy within 1 year was conducted from 2010 to 2015. All patients underwent a baseline 3-T multiparametric MRI (mpMRI) with endorectal coil and were selected for biopsy based on MR findings of a suspicious prostate lesion and high degree of clinical suspicion for cancer. Spearman correlation was performed to assess concordance between tpMRGB and final RP pathology among patients with and without previous transrectal ultrasound (TRUS)-guided biopsies. RESULTS: A total of 24 men met all eligibility requirements, with a median age of 65 years (interquartile range [IQR] 11.7). The median time from biopsy to RP was 85 days (IQR 50.5). Final pathology revealed Gleason 3 + 4 = 7 in 12 patients, 4 + 3 = 7 in 10 patients, and 4 + 4 = 8 in 2 patients. A strong correlation (ρ: +0.75, p < 0.001) between tpMRGB and RP results was observed, with Gleason scores concordant in 17 cases (71%). 16 of the 24 patients underwent prior TRUS biopsies. Subsequent tpMRGB revealed Gleason upgrading in 88% of cases, which was concordant with RP Gleason scores in 69% of cases (ρ: +0.75, p < 0.001). CONCLUSION: Final Gleason scores diagnosed by tpMRGB at 3-T correlate strongly with final RP surgical pathology. This may facilitate prostate cancer diagnosis, particularly in patients with negative or low-grade TRUS biopsy results in whom clinically significant cancer is suspected or detected on mpMRI.

Behringer PA, Herz C, Penzkofer T, Tuncali K, Tempany CM, Fedorov A. Open-Source Platform for Prostate Motion Tracking During in-Bore Targeted MRI-Guided Biopsy. Clin Image Based Proced. 2016;9401 :122-9.Abstract

Accurate sampling of cancer suspicious locations is critical in targeted prostate biopsy, but can be complicated by the motion of the prostate. We present an open-source software for intra-procedural tracking of the prostate and biopsy targets using deformable image registration. The software is implemented in 3D Slicer and is intended for clinical users. We evaluated accuracy, computation time and sensitivity to initialization, and compared implementations that use different versions of the Insight Segmentation Toolkit (ITK). Our retrospective evaluation used data from 25 in-bore MRI-guided prostate biopsy cases (343 registrations total). Prostate Dice similarity coefficient improved on average by 0.17 (p < 0.0001, range 0.02-0.48). Registration was not sensitive to operator variability. Computation time decreased significantly for the implementation using the latest version of ITK. In conclusion, we presented a fully functional open-source tool that is ready for prospective evaluation during clinical MRI-guided prostate biopsy interventions.

Fedorov A, Tuncali K, Panych LP, Fairhurst J, Hassanzadeh E, Seethamraju RT, Tempany CM, Maier SE. Segmented Diffusion-Weighted Imaging of the Prostate: Application to Transperineal In-bore 3T MR Image-guided Targeted Biopsy. Magn Reson Imaging. 2016;34 (8) :1146-54.Abstract

OBJECTIVE: This study aims to evaluate the applicability of using single-shot and multi-shot segmented diffusion-weighted imaging (DWI) techniques to support biopsy target localization in a cohort of targeted MRI-guided prostate biopsy patients. MATERIALS AND METHODS: Single-shot echo-planar diffusion-weighted imaging (SS-DWI) and multi-shot segmented (MS-DWI) were performed intra-procedurally on a 3Tesla system in a total of 35 men, who underwent in-bore prostate biopsy inside the scanner bore. Comparisons between SS-DWI and MS-DWI were performed with (in 16 men) and without (in 19 men) parallel coil acceleration (iPAT) for SS-DWI. Overall image quality and artifacts were scored by a radiologist and scores were compared with the Wilcoxon-Mann-Whitney rank test. Correlation between the presence of air and image quality scores was evaluated with Spearman statistics. To quantify distortion, the anteroposterior prostate dimension was measured in SS and MS b=0 diffusion- and T2-weighted images. Signal-to-noise ratio was estimated in a phantom experiment. Agreement and accuracy of targeting based on retrospective localization of restricted diffusion areas in DWI was evaluated with respect to the targets identified using multi-parametric MRI (mpMRI). RESULTS: Compared to SS-DWI without iPAT, the average image quality score in MS-DWI improved from 2.0 to 3.3 (p<0.005) and the artifact score improved from 2.3 to 1.4 (p<0.005). When iPAT was used in SS-DWI, the average image quality score in MS-DWI improved from 2.6 to 3.3 (p<0.05) and the artifact score improved from 2.1 to 1.4 (p<0.01). Image quality (ρ=-0.74, p<0.0005) and artifact scores (ρ=0.77, p<0.0005) both showed strong correlation with the presence of air in the rectum for the SS-DWI sequence without iPAT. These correlations remained significant when iPAT was enabled (ρ=-0.52, p<0.05 and ρ=0.64, p<0.01). For the comparison MS-DWI vs SS-DWI without iPAT, median differences between diffusion- and T2-weighted image gland measurements were 1.1(0.03-10.4)mm and 4.4(0.5-22.7)mm, respectively. In the SS-DWI-iPAT cohort, median gland dimension differences were 2.7(0.4-5.9)mm and 4.2(0.7-8.9)mm, respectively. Out of the total of 89 targets identified in mpMRI, 20 had corresponding restricted diffusion areas in SS-DWI and 28 in MS-DWI. No statistically significant difference was observed between the distances for the targets in the target-concordant SS- and MS-DWI restricted diffusion areas (5.5mm in SS-DWI vs 4.5mm in MS-DWI, p>0.05). CONCLUSIONS: MS-DWI applied to prostate imaging leads to a significant reduction of image distortion in comparison with SS-DWI. There is no sufficient evidence however to suggest that intra-procedural DWI can serve as a replacement for tracking of the targets identified in mpMRI for the purposes of targeted MRI-guided prostate biopsy.

Eslami S, Shang W, Li G, Patel N, Fischer GS, Tokuda J, Hata N, Tempany CM, Iordachita I. In-bore Prostate Transperineal Interventions with an MRI-guided Parallel Manipulator: System Development and Preliminary Evaluation. Int J Med Robot. 2016;12 (2) :199-213.Abstract

BACKGROUND: Robot-assisted minimally-invasive surgery is well recognized as a feasible solution for diagnosis and treatment of prostate cancer in humans. METHODS: This paper discusses the kinematics of a parallel 4 Degrees-of-Freedom (DOF) surgical manipulator designed for minimally invasive in-bore prostate percutaneous interventions through the patient's perineum. The proposed manipulator takes advantage of four sliders actuated by MRI-compatible piezoelectric motors and incremental rotary encoders. Errors, mostly originating from the design and manufacturing process, need to be identified and reduced before the robot is deployed in clinical trials. RESULTS: The manipulator has undergone several experiments to evaluate the repeatability and accuracy (about 1 mm in air (in x or y direction) at the needle's reference point) of needle placement, which is an essential concern in percutaneous prostate interventions. CONCLUSION: The acquired results endorse the sustainability, precision and reliability of the manipulator. Copyright © 2015 John Wiley & Sons, Ltd.

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