Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study

Importance Targeted magnetic resonance (MR)/ultrasound fusion prostate biopsy has been shown to detect prostate cancer. The implications of targeted biopsy alone vs standard extended-sextant biopsy or the 2 modalities combined are not well understood. Objective To assess targeted vs standard biopsy and the 2 approaches combined for the diagnosis of intermediate- to high-risk prostate cancer. Design, setting, and participants Prospective cohort study of 1003 men undergoing both targeted and standard biopsy concurrently from 2007 through 2014 at the National Cancer Institute in the United States. Patients were referred for elevated level of prostate-specific antigen (PSA) or abnormal digital rectal examination results, often with prior negative biopsy results. Risk categorization was compared among targeted and standard biopsy and, when available, whole-gland pathology after prostatectomy as the "gold standard." Interventions Patients underwent multiparametric prostate magnetic resonance imaging to identify regions of prostate cancer suspicion followed by targeted MR/ultrasound fusion biopsy and concurrent standard biopsy. Main outcomes and measures The primary objective was to compare targeted and standard biopsy approaches for detection of high-risk prostate cancer (Gleason score ≥ 4 + 3); secondary end points focused on detection of low-risk prostate cancer (Gleason score 3 + 3 or low-volume 3 + 4) and the biopsy ability to predict whole-gland pathology at prostatectomy. Results Targeted MR/ultrasound fusion biopsy diagnosed 461 prostate cancer cases, and standard biopsy diagnosed 469 cases. There was exact agreement between targeted and standard biopsy in 690 men (69%) undergoing biopsy. Targeted biopsy diagnosed 30% more high-risk cancers vs standard biopsy (173 vs 122 cases, P Conclusions and relevance Among men undergoing biopsy for suspected prostate cancer, targeted MR/ultrasound fusion biopsy, compared with standard extended-sextant ultrasound-guided biopsy, was associated with increased detection of high-risk prostate cancer and decreased detection of low-risk prostate cancer. Future studies will be needed to assess the ultimate clinical implications of targeted biopsy. Trial registration clinicaltrials.gov Identifier: NCT00102544.

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Comparison of MR/Ultrasound Fusion–Guided Biopsy With Ultrasound-Guided Biopsy for the Diagnosis of Prostate Cancer

https://www.europeanurology.com/article/S0302-2838(15)00036-6/pdf/can-clinically-significant-prostate-cancer-be-detected-with-multiparametric-magnetic-resonance-imaging-a-systematic-review-of-the-literature

Can Clinically Significant Prostate Cancer Be Detected with Multiparametric Magnetic Resonance Imaging? A Systematic Review of the Literature

https://www.europeanurology.com/article/S0302-2838(12)00695-1/pdf/image-guided-prostate-biopsy-using-magnetic-resonance-imaging-x02013-derived-targets-a-systematic-review

Image-guided prostate biopsy using magnetic resonance imaging-derived targets: a systematic review.

https://www.europeanurology.com/article/S0302-2838(13)00598-8/pdf/Magnetic+Resonance+Imaging/Ultrasound%E2%80%93Fusion+Biopsy+Significantly+Upgrades+Prostate+Cancer+Versus+Systematic+12-core+Transrectal+Ultrasound+Biopsy

Magnetic Resonance Imaging/Ultrasound-Fusion Biopsy Significantly Upgrades Prostate Cancer Versus Systematic 12-core Transrectal Ultrasound Biopsy

Magnetic Resonance Imaging/Ultrasound Fusion Guided Prostate Biopsy Improves Cancer Detection Following Transrectal Ultrasound Biopsy and Correlates With Multiparametric Magnetic Resonance Imaging

This paper summarizes our work over the past several years in developing an image-guided system based on electromagnetic tracking for abdominal interventions. The paper begins with a review of computer-aided surgery and electromagnetic tracking. We next describe our image-guided system along with phantom and animal studies. We then present some technical issues in improving accuracy including pivot calibration, dynamic referencing, and registration using two 5 degree-of-freedom sensors. Electromagnetic tracking has great potential for assisting physicians in precision placement of instruments during minimally invasive interventions. However, the accuracy of these systems needs to be validated in the clinical environment and issues such as respiratory motion and organ deformation need to be addressed

Electromagnetic Tracking for Image-Guided Abdominal Procedures: Overall System and Technical Issues

This paper investigates the possibility of using the motion of a patient's anterior surface in combination with a motion model to compensate for internal respiratory motion during tracked biopsies. Position data from two electromagnetically tracked sensors, one placed on the patient's sternum, the other incorporated into a biopsy needle, were acquired during a liver biopsy. The data were used to evaluate the correlation between the position measurements of the two sensors and to derive an affine motion model to assess respiratory motion compensation for image-guided interventional procedures. The correlation reached up to 94% for ranges of steady respiration. The residual motion of the internal sensor after compensation is reduced by a factor of approximately four.

Respiratory motion compensation with tracked internal and external sensors during CT-guided procedures.

A system for fusion of realtime transrectal ultrasound (TRUS) with pre-acquired 3D images of the prostate was designed and demonstrated in phantoms and volunteer patients. Biopsy guides for endocavity ultrasound transducers were equipped with customized 6 degree-of-freedom (DoF) electromagnetic (EM) tracking sensors, compatible with the Aurora EM tracking system (Northern Digital Inc, NDI, Waterloo, ON, Canada). The biopsy guides were attached to an ultrasound probe and calibrated to map tracking coordinates with ultrasound image coordinates. Six cylindrical gold seeds were placed in a prostate phantom to serve as fiducial markers. The fiducials were first identified manually in 3T magnetic resonance (MR) images collected with an endorectal coil. The phantom was then imaged with tracked realtime TRUS and the fiducial markers were identified in the live image using custom software. Rigid registrations between MR and ultrasound image space were computed and evaluated using subsets of the fiducial markers. Twelve patients were scanned with 3T MRI and TRUS for biopsy and seed placement. In ten patients, volumetric ultrasound images were reconstructed from 2D sweeps of the prostate and were manually registered with the MR. The rigid registrations were used to display live TRUS images fused with spatially corresponding realtime multiplanar reconstructions (MPRs) of the MR image volume. Registration accuracy was evaluated by segmenting the prostate in the MR and volumetric ultrasound and computing distance measures between the two segmentations. In the phantom experiments, registration accuracies of 2.2 to 2.3 mm were achieved. In the patient studies, the average root mean square distance between the MR and TRUS segmentations was 3.1 mm, the average Hausdorff distance was 9.8 mm. Deformation of the prostate during MR and TRUS scan was identified as the primary source of error. Realtime MR/TRUS image fusion is feasible and is a promising approach to improved target visualization during TRUS-guided biopsy or therapy procedures.

Fusion of real-time transrectal ultrasound with pre-acquired MRI for multi-modality prostate imaging

Methods, systems, and devices for assisting or performing an image-guided prostate procedure are disclosed. A needle assembly includes a needle guide, a needle device, a position sensor and additional features. The position sensor allows for the tracking of the needle assembly. A method for performing image-guided prostate procedures includes pre-operative procedures and intra-operative procedures. The pre-operative procedures include imaging studies to model the prostate and identify targets. The pre-operative procedures models are used during a prostate procedure to track the target and the devices used for the procedure. A system for performing image-guided procedures includes the needle assembly and other components.

Neil Glossop

Papers

Magnetic Resonance Imaging/Ultrasound Fusion Guided Prostate Biopsy Improves Cancer Detection Following Transrectal Ultrasound Biopsy and Correlates With Multiparametric Magnetic Resonance Imaging

Electromagnetic Tracking for Image-Guided Abdominal Procedures: Overall System and Technical Issues

Respiratory motion compensation with tracked internal and external sensors during CT-guided procedures.

Fusion of real-time transrectal ultrasound with pre-acquired MRI for multi-modality prostate imaging

System, method and device for prostate diagnosis and intervention