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.
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

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.
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.

Penzkofer T, Tuncali K, Fedorov A, Song S-E, Tokuda J, Fennessy FM, Vangel MG, Kibel AS, Mulkern RV, Wells WM, et al. Transperineal In-Bore 3-T MR Imaging-guided Prostate Biopsy: A Prospective Clinical Observational Study. Radiology. 2015;274 (1) :170-80.Abstract

PURPOSE: To determine the detection rate, clinical relevance, Gleason grade, and location of prostate cancer ( PCa prostate cancer ) diagnosed with and the safety of an in-bore transperineal 3-T magnetic resonance (MR) imaging-guided prostate biopsy in a clinically heterogeneous patient population. MATERIALS AND METHODS: This prospective retrospectively analyzed study was HIPAA compliant and institutional review board approved, and informed consent was obtained. Eighty-seven men (mean age, 66.2 years ± 6.9) underwent multiparametric endorectal prostate MR imaging at 3 T and transperineal MR imaging-guided biopsy. Three subgroups of patients with at least one lesion suspicious for cancer were included: men with no prior PCa prostate cancer diagnosis, men with PCa prostate cancer who were undergoing active surveillance, and men with treated PCa prostate cancer and suspected recurrence. Exclusion criteria were prior prostatectomy and/or contraindication to 3-T MR imaging. The transperineal MR imaging-guided biopsy was performed in a 70-cm wide-bore 3-T device. Overall patient biopsy outcomes, cancer detection rates, Gleason grade, and location for each subgroup were evaluated and statistically compared by using χ(2) and one-way analysis of variance followed by Tukey honestly significant difference post hoc comparisons. RESULTS: Ninety biopsy procedures were performed with no serious adverse events, with a mean of 3.7 targets sampled per gland. Cancer was detected in 51 (56.7%) men: 48.1% (25 of 52) with no prior PCa prostate cancer , 61.5% (eight of 13) under active surveillance, and 72.0% (18 of 25) in whom recurrence was suspected. Gleason pattern 4 or higher was diagnosed in 78.1% (25 of 32) in the no prior PCa prostate cancer and active surveillance groups. Gleason scores were not assigned in the suspected recurrence group. MR targets located in the anterior prostate had the highest cancer yield (40 of 64, 62.5%) compared with those for the other parts of the prostate (P < .001). CONCLUSION: In-bore 3-T transperineal MR imaging-guided biopsy, with a mean of 3.7 targets per gland, allowed detection of many clinically relevant cancers, many of which were located anteriorly.

Penzkofer T, Tempany CM. Prostate Cancer Detection and Diagnosis: The Role of MR and its Comparison with Other Diagnostic Modalities - A Radiologist's Perspective. NMR Biomed. 2014;27 (1) :3-15.Abstract

It is now universally recognized that many prostate cancers are over-diagnosed and over-treated. The European Randomized Study of Screening for Prostate Cancer from 2009 evidenced that, to save one man from death from prostate cancer, over 1400 men need to be screened, and 48 need to undergo treatment. The detection of prostate cancer is traditionally based on digital rectal examination (DRE) and the measurement of serum prostate-specific antigen (PSA), followed by ultrasound-guided biopsy. The primary role of imaging for the detection and diagnosis of prostate cancer has been transrectal ultrasound (TRUS) guidance during biopsy. Traditionally, MRI has been used primarily for the staging of disease in men with biopsy-proven cancer. It has a well-established role in the detection of T3 disease, planning of radiation therapy, especially three-dimensional conformal or intensity-modulated external beam radiation therapy, and planning and guiding of interstitial seed implant or brachytherapy. New advances have now established that prostate MRI can accurately characterize focal lesions within the gland, an ability that has led to new opportunities for improved cancer detection and guidance for biopsy. Two new approaches to prostate biopsy are under investigation. Both use pre-biopsy MRI to define potential targets for sampling, and the biopsy is performed either with direct real-time MR guidance (in-bore) or MR fusion/registration with TRUS images (out-of-bore). In-bore and out-of-bore MRI-guided prostate biopsies have the advantage of using the MR target definition for the accurate localization and sampling of targets or suspicious lesions. The out-of-bore method uses combined MRI/TRUS with fusion software that provides target localization and increases the sampling accuracy of TRUS-guided biopsies by integrating prostate MRI information with TRUS. Newer parameters for each imaging modality, such as sonoelastography or shear wave elastography, contrast-enhanced ultrasound and MRI elastography, show promise to further enrich datasets.