MRI-targeted or standard biopsy for prostate-cancer diagnosis

Background Multiparametric magnetic resonance imaging (MRI), with or without targeted biopsy, is an alternative to standard transrectal ultrasonography-guided biopsy for prostate-cancer detection in men with a raised prostate-specific antigen level who have not undergone biopsy. However, comparative evidence is limited. Methods In a multicenter, randomized, noninferiority trial, we assigned men with a clinical suspicion of prostate cancer who had not undergone biopsy previously to undergo MRI, with or without targeted biopsy, or standard transrectal ultrasonography-guided biopsy. Men in the MRI-targeted biopsy group underwent a targeted biopsy (without standard biopsy cores) if the MRI was suggestive of prostate cancer; men whose MRI results were not suggestive of prostate cancer were not offered biopsy. Standard biopsy was a 10-to-12-core, transrectal ultrasonography-guided biopsy. The primary outcome was the proportion of men who received a diagnosis of clinically significant cancer. Secondary outcomes included the proportion of men who received a diagnosis of clinically insignificant cancer. Results A total of 500 men underwent randomization. In the MRI-targeted biopsy group, 71 of 252 men (28%) had MRI results that were not suggestive of prostate cancer, so they did not undergo biopsy. Clinically significant cancer was detected in 95 men (38%) in the MRI-targeted biopsy group, as compared with 64 of 248 (26%) in the standard-biopsy group (adjusted difference, 12 percentage points; 95% confidence interval [CI], 4 to 20; P=0.005). MRI, with or without targeted biopsy, was noninferior to standard biopsy, and the 95% confidence interval indicated the superiority of this strategy over standard biopsy. Fewer men in the MRI-targeted biopsy group than in the standard-biopsy group received a diagnosis of clinically insignificant cancer (adjusted difference, -13 percentage points; 95% CI, -19 to -7; P<0.001). Conclusions The use of risk assessment with MRI before biopsy and MRI-targeted biopsy was superior to standard transrectal ultrasonography-guided biopsy in men at clinical risk for prostate cancer who had not undergone biopsy previously. (Funded by the National Institute for Health Research and the European Association of Urology Research Foundation; PRECISION ClinicalTrials.gov number, NCT02380027 .)

Transurethral convective water vapor as a treatment for lower urinary tract symptomatology due to benign prostatic hyperplasia using the Rezūm® system: evaluation of acute ablative capabilities in the human prostate

BACKGROUND: The purpose of this study was to assess the acute ablative characteristics of transurethral convective water vapor (steam) using the Rezūm(®) system in men with benign prostatic hyperplasia through histologic and radiographic studies. METHODS: Seven patients were treated with transurethral intraprostatic injections of sterile steam under endoscopic visualization followed by previously scheduled adenectomies. The extirpated adenomas were grossly examined followed by whole mount sectioning and staining with triphenyl-tetrazolium chloride (TTC) to evaluate thermal ablation. Histology was performed after hematoxylin and eosin staining on one prostate. After review of results from the first patient cohort, an additional 15 patients with clinical benign prostatic hyperplasia were treated followed by gadolinium-enhanced magnetic resonance imaging (MRI) at one week. RESULTS: In the first patient cohort, gross examination of TTC-stained tissue showed thermal ablation in the transition zone. In addition, there was a distinct interface between viable and necrotic prostatic parenchyma. Histopathologic examination revealed TTC staining-outlined necrotic versus viable tissue. Gadolinium-enhanced MRIs in the cohort of 15 patients demonstrated lesion defects in all patients at 1 week post-procedure. Coalesced lesions were noted with a mean (± standard deviation) lesion volume of 9.6±8.5 cm(3). The largest lesion volume was 35.1 cm(3). Ablation using vapor was rapid and remained confined to the transition zone, consistent with the thermodynamic principles of convective thermal energy transfer. CONCLUSION: Thermal ablation was observed in all specimens. The resulting coalescing ablative lesions, as seen on MRI, were confined to the transition zone. These studies confirm the ablative capabilities of vapor, validate the thermodynamic principles of convective heating, and allow for further clinical studies

Characterizing ProstivaTM RF Treatments of the Prostate for BPH with Gadolinium-Enhanced MRI

Transurethral needle ablation (TUNA) is an accepted and effective therapy for the treatment of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). ProstivaTM (Medtronic, Shoreview, MN) is the newest-generation device, which includes a new needle design and radio frequency (RF) generator. This device creates temperatures of 120°C and necrotic lesions in less than 2.5 min. Using previously described techniques, we analyzed dynamic, gadolinium-enhanced MRIs to characterize the ablative properties of the new ProstivaTM RF device

Evaluation of a perineal access device for MRI-guided prostate interventions

This paper describes a perineal access tool for MRI-guided prostate interventions and evaluates it using a phantom study. The development of this device has been driven by the clinical need and a close collaboration effort. The device seamlessly fits into the workflow of MRI-guided prostate procedures such as cryoablation and biopsies. It promises a significant cut in the procedure time, accurate needle placement, lower number of insertions, and a potential for better patient outcomes. The current embodiment includes a frame which is placed next to the perineum and incorporates both visual and MRI-visible markers. These markers are automatically detected both in MRI and by a pair of stereo cameras (optical head) allowing for automatic optical registration. The optical head illuminates the procedure area and can track instruments and ultrasound probes. The frame has a window to access the perineum. Multiple swappable grids may be placed in this window depending on the application. It is also possible to entirely remove the grid for freehand procedures. All the components are designed to be used inside the MRI suite. To test this system, we built a custom phantom with MRI visible targets and planned 21 needle insertions with three grid types using the SCENERGY software. With an average insertion depth of about 85 mm, the average error of needle tip placement was 2.74 mm. We estimated the error by manually segmenting the needle tip in post-insertion MRIs of the phantom and comparing that to the plan

Characterizing TUNA® ablative treatments of the prostate for benign hyperplasia with gadolinium-enhanced magnetic resonance imaging

Background and Purpose: Transurethral Needle Ablation of the prostate (TUNA®) has been accepted as an office-based treatment for benign prostatic hyperplasia (BPH) for many years. Clinical outcomes have been reported, but the amount and location of the necrosis produced have yet to be characterized. The necrosis caused by TUNA was evaluated by gadolinium-enhanced magnetic resonance imaging (MRI) of the pelvis. Patients and Methods: Twelve patients with BPH/lower urinary-tract symptoms underwent standard TUNA, and MRI scans with gadolinium enhancement were performed before and 1 week after treatment. The images were studied using Analyze® software to quantify the amount of necrosis compared with the prostatic volume. Transverse, coronal, and sagittal images were obtained to identify the location of the necrosis. Results: New gadolinium defects were seen in all patients after TUNA. The lesions coalesced into continuous areas of necrosis and correlated with the site of needle placement.