focal-laser-ablation-of-prostate-cancer-an-office-procedure

Focal Laser Ablation of Prostate Cancer: An Office Procedure

In this article, we describe and illustrate an outpatient procedure for focal laser ablation (FLA) of prostate cancer (PCa). The procedure is conceptually ...

University of California Los Angeles

Targeted biopsy of lesions identified on magnetic resonance imaging may enhance the detection of clinically relevant prostate cancers. We evaluated prostate cancer detection rates in 171 consecutive men using magnetic resonance ultrasound fusion prostate biopsy.

Targeted biopsy in the detection of prostate cancer using an office based magnetic resonance ultrasound fusion device.

Established in 1994, the Epstein histological criteria (Gleason score 6 or less, 2 or fewer cores positive and 50% or less of any core) have been widely used to select men for active surveillance. However, with the advent of targeted biopsy, which may be more accurate than conventional biopsy, we reevaluated the likelihood of reclassification upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion.

Targeted prostate biopsy in select men for active surveillance: do the Epstein criteria still apply?

We have developed a system for evaluating magnetic resonance imaging of prostate cancer, using patient-specific 3D printed molds to facilitate MR-histology correlation. Prior to radical prostatectomy a patient receives a multiparametric MRI, which an expert genitourinary radiologist uses to identify and contour regions suspicious for disease. The same MR series is used to generate a prostate contour, which is the basis for design of a patient-specific mold. The 3D printed mold contains a series of evenly spaced parallel slits, each of which corresponds to a known MRI slice. After surgery, the patient's specimen is enclosed within the mold, and all whole-mount levels are obtained simultaneously through use of a multi-bladed slicing device. The levels are then formalin fixed, processed, and delivered to an expert pathologist, who identifies and grades all lesions within the slides. Finally, the lesion contours are loaded into custom software, which elastically warps them to fit the MR prostate contour. The suspicious regions on MR can then be directly compared to lesions on histology. Furthermore, the false-negative and false-positive regions on MR can be retrospectively examined, with the ultimate goal of developing methods for improving the predictive accuracy of MRI. This work presents the details of our analysis method, following a patient from diagnosis through the MR-histology correlation process. For this patient MRI successfully predicted the presence of cancer, but true lesion volume and extent were underestimated. Most cancer-positive regions missed on MR were observed to have patterns of low T2 signal, suggesting that there is potential to improve sensitivity. 

A system for evaluating magnetic resonance imaging of prostate cancer using patient-specific 3D printed molds.

Lessons learned during a 6-year experience with more than 1200 patients undergoing targeted prostate biopsy via MRI/ultrasound fusion are reported: (1) the procedure is safe and efficient, requiring some 15-20 minutes in an office setting; (2) MRI is best performed by a radiologist with specialized training, using a transabdominal multiparametric approach and preferably a 3T magnet; (3) grade of MRI suspicion is the most powerful predictor of biopsy results, eg, Grade 5 usually represents cancer; (4) some potentially important cancers (15%-30%) are MRI-invisible; (5) Targeted biopsies provide >80% concordance with whole-organ pathology. Early enthusiasm notwithstanding, cost-effectiveness is yet to be resolved, and the technologies remain in evolution.

Targeted Prostate Biopsy: Lessons Learned Midst the Evolution of a Disruptive Technology.

We assessed whether changes in serial multiparametric magnetic resonance imaging can help predict the pathological progression of prostate cancer in men on active surveillance.

Serial Magnetic Resonance Imaging in Active Surveillance of Prostate Cancer: Incremental Value.

We evaluated the accuracy of magnetic resonance imaging in determining the size and shape of localized prostate cancer.

Magnetic Resonance Imaging Underestimation of Prostate Cancer Geometry: Use of Patient Specific Molds to Correlate Images with Whole Mount Pathology.

We sought to determine the rate of upgrading to Gleason score 4 + 3 or greater using targeted biopsy for diagnosis and monitoring in men undergoing active surveillance of prostate cancer.

Targeted Biopsy to Detect Gleason Score Upgrading during Active Surveillance for Men with Low versus Intermediate Risk Prostate Cancer.

Herein, we describe a case of a 63-year-old male who underwent magnetic resonance imaging (MRI)-guided biopsy of a suspicious lesion in the prostate followed by focal laser ablation. Radical prostatectomy was performed 15 months following focal laser ablation for persistent cancer adjacent to the treatment zone. We provide images from the initial MRI, postablation MRI, and the whole-mount radical prostatectomy specimen. The present case demonstrates the confined, localized effect of focal laser ablation, and also illustrates the advantage of expanded treatment margins.

Focal Laser Ablation of Prostate Cancer.

Focal laser ablation is a potential treatment in some men with prostate cancer. Currently focal laser ablation is performed by radiologists in a magnetic resonance imaging unit (in bore). We evaluated the safety and feasibility of performing focal laser ablation in a urology clinic (out of bore) using magnetic resonance imaging-ultrasound fusion for guidance.

Focal Laser Ablation of Prostate Cancer: Feasibility of Magnetic Resonance Imaging-Ultrasound Fusion for Guidance.

We assessed focal therapy eligibility in men who underwent multiparametric magnetic resonance imaging and targeted biopsy with correlation to whole mount histology after radical prostatectomy.

Focal Therapy Eligibility Determined by Magnetic Resonance Imaging/Ultrasound Fusion Biopsy.

Patient-specific 3D-printed molds and ex vivo MRI of the resected prostate have been two important strategies to align MRI with whole-mount histopathology (WMHP) for prostate cancer (PCa) research, but the combination of these two strategies has not been systematically evaluated.

A system using patient-specific 3D-printed molds to spatially align in vivo MRI with ex vivo MRI and whole-mount histopathology for prostate cancer research.

Shyam Natarajan

University of California Los Angeles

Focal Laser Ablation of Prostate Cancer: An Office Procedure