To Transrectal Ultrasound Research Articles

The Diagnostic Value of Multiparametric-MRI in Locating Prostate Cancer in Comparison with Transrectal Ultrasound-Guided Biopsy

Purpose: The present study was designed to evaluate the potential efficacy of Multiparametric-Magnetic Resonance Imaging (MP-MRI) in the detection of prostate cancer locations compared to Transrectal Ultrasound (TRUS) guided biopsy, as the gold standard method.
 Materials and Methods: A total of 66 subjects participated in this cross-sectional study. All individuals underwent MP-MRI imaging before the prostate TRUS. The findings of either method have been investigated and the comparison had been made using the Chi-squared test.
 Results: The sensitivity and specificity of the MP-MRI in the diagnosis of prostate cancer were 81.8% and 93.9%, respectively. The positive and negative predictive values were 93.1% and 83.8%, respectively.
 Conclusion: The current study indicates that the MP-MRI imaging method has sufficient sensitivity and specificity for detecting the location of prostate cancer and can potentially be employed as a clue-providing method prior to the TRUS-guided biopsy.

Viability of focal dose escalation to prostate cancer intraprostatic lesions using HDR prostate brachytherapy

This study aimed to determine the viability of focal dose escalation to prostate cancer intraprostatic lesions (IPLs) from multiparametric magnetic resonance (mpMRI) and prostate-specific membrane antigen positron emission tomography (PSMA-PET) images using high-dose-rate (HDR) prostate brachytherapy (pBT). Retrospective data from 20 patients treated with HDR pBT was utilized. The interobserver contouring variability of 5 observers was quantified using the dice similarity coefficient (DSC) and mean distance to agreement (MDA). Uncertainty in propagating IPL contours to trans-rectal ultrasound (TRUS) was quantified using a tissue equivalent prostate phantom. Feasibility of incorporating IPLs into HDR pBT planning was tested on retrospective patient data. The average observer DSC was 0.65 (PSMA-PET) and 0.52 (mpMRI). The uncertainty in propagating IPL contours was 0.6 mm (PSMA-PET), and 0.4 mm (mpMRI). Uncertainties could be accounted for by expanding IPL contours by 2 mm to create IPL PTVs. The mean D98% achieved using HDR pBT was 166% and 135% for the IPL and IPL PTV contours, respectively. Focal dose escalation to IPLs identified on either PSMA-PET or mpMRI is viable using TRUS-based HDR pBT. Utilizing HDR pBT allows dose escalation of up to 166% of the prescribed dose to the prostate.

Giant prostatic enlargement: A presentation of a rare asymptomatic case

Benign prostatic hyperplasia is a histological diagnosis and the most frequent benign tumor in older men, and its incidence strongly correlates with advanced age. Giant prostate enlargement (GPE), also known as giant prostatic hyperplasia, is a term given for severely enlarged prostates that weigh more than 500g. GPE cases reported in literature is less than 30. We describe our experience of removing previously asymptomatic 528g prostate by open transvesical prostatectomy. According to transrectal ultrasound (TRUS) the prostate size is 482 ml and prostate‑specific antigen level of 5.1 ng/ml. Histological examination showed nodular prostatic hyperplasia, an adenomatous variant with foci of cystic atrophy, chronic prostatitis. The patient's post-operative recovery went without any relapses and complications.

MRI determined prostate volume and the incidence of prostate cancer on MRI-fusion biopsy: a systemic review of reported data for the last 20years.

Magnetic resonance imaging (MRI) is a precise, systemic and advantageous imaging technique when compared to transrectal ultrasound (TRUS) which is very operator dependent. The negative correlation between prostate volume and the incidence of prostate cancer (PCa) obtained by TRUS biopsy has been well documented in the literature. The purpose of this systemic review is analyzing the reported MRI-fusion study results on prostate biopsies regarding any correlation between prostate volume and the incidence of PCa. After defining the inclusion and exclusion criteria an in-depth review were performed between 01.01.2000 and 02.08.2022 using the PubMed database and applying the "PRISMA" guidelines. Twelve studies qualified, and all showed an inverse/negative relationship between prostate volume and incidence of PCa. Sample sizes ranged from 33 to 2767 patients in single and multi-institutional studies. All studies showed a statistically significant inverse relationship with a p value < 0.05. The graph summarizing all of studies and using Fisher's method revealed a highly significant combined p level of 0.00001. Additionally, not one single study was found showing the contrary (a positive correlation between prostate size and the incidence of PCa). To our knowledge, this is the first systemic review of reported MRI-Fusion data on the incidence of PCa in correlation with prostate volume. This MRI review confirms previous TRUS-biopsy studies which demonstrated an inverse relationship between prostate volume and the incidence of PCa, and thus further supports the hypothesis that large prostates size may be protective against PCa when compared to smaller prostates.

PD39-12 A PROSPECTIVE TRIAL OF MULTIPARAMETRIC MAGNETIC RESONANCE OF THE PROSTATE USE TO AVOID BIOPSIES IN PATIENTS WITH ELEVATED PROSTATE SPECIFIC ANTIGEN AND SURGICAL INDICATION FOR BENIGN PROSTATIC HYPERPLASIA

You have accessJournal of UrologyCME1 May 2022PD39-12 A PROSPECTIVE TRIAL OF MULTIPARAMETRIC MAGNETIC RESONANCE OF THE PROSTATE USE TO AVOID BIOPSIES IN PATIENTS WITH ELEVATED PROSTATE SPECIFIC ANTIGEN AND SURGICAL INDICATION FOR BENIGN PROSTATIC HYPERPLASIA Marcelo Wroclawski, Lucas Takemura, Felipe Gushiken, Breno Amaral, Paulo Kayano, Ronaldo Baroni, Bianca Bianco, Arie Carneiro, and Gustavo Lemos Marcelo WroclawskiMarcelo Wroclawski More articles by this author , Lucas TakemuraLucas Takemura More articles by this author , Felipe GushikenFelipe Gushiken More articles by this author , Breno AmaralBreno Amaral More articles by this author , Paulo KayanoPaulo Kayano More articles by this author , Ronaldo BaroniRonaldo Baroni More articles by this author , Bianca BiancoBianca Bianco More articles by this author , Arie CarneiroArie Carneiro More articles by this author , and Gustavo LemosGustavo Lemos More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002597.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Patients with benign prostatic hyperplasia (BPH) may have increased prostate specific antigen (PSA) levels, posing a dilemma as to whether perform a prostate biopsy to rule out a concomitant prostate cancer (PCa) before a surgical procedure. Multiparametric magnetic resonance imaging (mpMRI) has increased the detection of clinically significant PCa and may aid the decision to biopsy patients who are suspicious for PCa. This study aimed to evaluate if mpMRI could safely prescind the prostate biopsy in patients who will undergo a BPH procedure. METHODS: Interim analysis of a prospective study including 84 men with surgical indication due to BPH and concomitantly elevated PSA levels (PSA ≥4 ng/ml, or PSA ≥2 ng/ml if using 5-alpha-reductase inhibitor). All patients underwent 1.5 Tesla mpMRI prior to transrectal ultrasound (TRUS) biopsy. Additional fragments were obtained with the fusion guided technique in cases where mpMRI identified focal lesions. Biopsy histopathological results were used as the standard of reference. Two scenarios were evaluated: scenario 1, considering mpMRI PIRADS 1 and 2 as negative; and scenario 2, considering PIRADS 1, 2 and 3 as negative. Clinically significant PCa was defined as ISUP ≥2. RESULTS: Median age was 72.5 years (53-86), median PSA was 8.06 ng/ml (2.0-39.87) and median prostatic volume was 119.80 cc (30-342). Scenario 1: mpMRI sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for any PCa on biopsy was 65.2%, 68.8%, 44.1%, 84% and 67.8%. For clinically significant PCa, they were 81.8%, 65.7%, 26.4%, 96% and 67.8%, respectively, for the same measures. Scenario 2: mpMRI sensitivity, specificity, PPV, NPV and accuracy for any PCa on biopsy was 39.1%, 91.8%, 64.2%, 80% and 77.3%. For clinically significant PCa, they were 72.7%, 91.7%, 57.1%, 95.7% and 89.2%, respectively, for the same measures. CONCLUSIONS: Prostate mpMRI may prevent unnecessary biopsies in patients with elevated PSA and surgical indication due to BPH, given its high negative predictive value. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e657 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Marcelo Wroclawski More articles by this author Lucas Takemura More articles by this author Felipe Gushiken More articles by this author Breno Amaral More articles by this author Paulo Kayano More articles by this author Ronaldo Baroni More articles by this author Bianca Bianco More articles by this author Arie Carneiro More articles by this author Gustavo Lemos More articles by this author Expand All Advertisement PDF DownloadLoading ...

EDITORIAL COMMENT

We would like to thank the editors for their comment on “Preventing prostate biopsy complications: to Augment or to Swab”. They present some of the challenges to implementing a rectal swab prior to transrectal ultrasound (TRUS) biopsy, and offer an alternative using the transperineal (TP) biopsy approach.

Value of MRI texture analysis for predicting new Gleason grade group.

To explore the potential value of multiparametric magnetic resonance imaging (mpMRI) texture analysis (TA) to predict new Gleason Grade Group (GGG). Fifty-eight lesions of fifty patients who underwent mpMRI scanning, including T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) prior to trans-rectal ultrasound (TRUS)-guided core prostate biopsy, were retrospectively enrolled. TA parameters were obtained by the postprocessing software, and each lesion was assigned to its corresponding GGG. TA parameters derived from T2WI and DWI were statistically analyzed in detail. Energy, inertia, and correlation derived from apparent diffusion coefficient (ADC) maps and T2WI had a statistically significant difference among the five groups. Kurtosis, energy, inertia, correlation on ADC maps and Energy, inertia on T2WI were moderately related to the GGG trend. ADC-energy and T2-energy were significant independent predictors of the GGG trend. ADC-energy, T2WI-energy, and T2WI-correlation had a statistically significant difference between GGG1 and GGG2-5. ADC-energy were significant independent predictors of the GGG1. ADC-energy, T2WI-energy, and T2WI-correlation showed satisfactory diagnostic efficiency of GGG1 (area under the curve (AUC) 84.6, 74.3, and 83.5%, respectively), and ADC-energy showed excellent sensitivity and specificity (88.9 and 95.1%, respectively). TA parameters ADC-energy and T2-energy played an important role in predicting GGG trend. Both ADC-energy and T2-correlation produced a high diagnostic power of GGG1, and ADC-energy was perfect predictors of GGG1. TA parameters were innovatively used to predict new GGG trend, and the predictive factors of GGG1 were screen out.

Prediction of Pathological Upgrading at Radical Prostatectomy in Prostate Cancer Eligible for Active Surveillance: A Texture Features and Machine Learning-Based Analysis of Apparent Diffusion Coefficient Maps.

ObjectiveTo evaluate a combination of texture features and machine learning-based analysis of apparent diffusion coefficient (ADC) maps for the prediction of Grade Group (GG) upgrading in Gleason score (GS) ≤6 prostate cancer (PCa) (GG1) and GS 3 + 4 PCa (GG2).Materials and methodsFifty-nine patients who were biopsy-proven to have GG1 or GG2 and underwent MRI examination with the same MRI scanner prior to transrectal ultrasound (TRUS)-guided systemic biopsy were included. All these patients received radical prostatectomy to confirm the final GG. Patients were divided into training cohort and test cohort. 94 texture features were extracted from ADC maps for each patient. The independent sample t-test or Mann−Whitney U test was used to identify the texture features with statistically significant differences between GG upgrading group and GG non-upgrading group. Texture features of GG1 and GG2 were compared based on the final pathology of radical prostatectomy. We used the least absolute shrinkage and selection operator (LASSO) algorithm to filter features. Four supervised machine learning methods were employed. The prediction performance of each model was evaluated by area under the receiver operating characteristic curve (AUC). The statistical comparison between AUCs was performed.ResultsSix texture features were selected for the machine learning models building. These texture features were significantly different between GG upgrading group and GG non-upgrading group (P < 0.05). The six features had no significant difference between GG1 and GG2 based on the final pathology of radical prostatectomy. All machine learning methods had satisfactory predictive efficacy. The diagnostic performance of nearest neighbor algorithm (NNA) and support vector machine (SVM) was better than random forests (RF) in the training cohort. The AUC, sensitivity, and specificity of NNA were 0.872 (95% CI: 0.750−0.994), 0.967, and 0.778, respectively. The AUC, sensitivity, and specificity of SVM were 0.861 (95%CI: 0.732−0.991), 1.000, and 0.722, respectively. There had no significant difference between AUCs in the test cohort.ConclusionA combination of texture features and machine learning-based analysis of ADC maps could predict PCa GG upgrading from biopsy to radical prostatectomy non-invasively with satisfactory predictive efficacy.

Value of MRI texture analysis for predicting high-grade prostate cancer

PurposeTo explore the potential value of MRI texture analysis (TA) combined with prostate-related biomarkers to predict high-grade prostate cancer (HGPCa). Materials and methodsEighty-five patients who underwent MRI scanning, including T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) prior to trans-rectal ultrasound (TRUS)-guided core prostate biopsy, were retrospectively enrolled. TA parameters derived from T2WI and DWI, prostate-specific antigen (PSA), and free PSA (fPSA) were compared between the HGPCa and non-high-grade prostate cancer (NHGPCa) groups using independent Student's t-test and the Mann-Whitney U test. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the predictive value for HGPCa. ResultsUnivariate analysis showed that PSA and entropy based on apparent diffusion coefficient (ADC) map differed significantly between the HGPCa and NHGPCa groups and showed higher diagnostic values for HGPCa (area under the curve (AUC) = 82.0% and 80.0%, respectively). Logistic regression and ROC curve analyses revealed that kurtosis, skewness and entropy derived from ADC maps had diagnostic power to predict HGPCa; when the three texture parameters were combined, the area under the ROC curve reached the maximum (AUC = 84.6%; 95% confidence interval (CI): 0.758, 0.935; P = 0.000). ConclusionTA parameters derived from ADC may be a valuable tool in predicting HGPCa. The combination of specific textural parameters extracted from ADC map may be additional tools to predict HGPCa.

Comparative evaluation of bilateral pudendal nerve blockade and periprostatic nerve block in transrectal ultrasound guided prostate biopsy: a prospective randomised trial.

IntroductionAlthough the periprostatic nerve block (PNB) is accepted as the standard method for local anesthesia prior to transrectal ultrasound (TRUS)-guided prostate biopsy, it is not the most ideal method. We aimed to analyze the effectiveness and safety of bilateral pudendal nerve blockage (PuNB) by comparing with PNB.Material and methodsBetween June 2019 and October 2019, a total of 108 patients with elevated serum prostate specific antigen values (PSA ≥4 ng/ml) and/or abnormal digital rectal examination findings were included in the study. After exclusion criteria, the remaining 91 patients were randomly divided into two groups as PuNB (n = 46) and PNB (n = 45). Pain during local anesthesia application was recorded as a visual analog scale (VAS) 1, pain during placement of the rectal probe and manipulation was recorded as VAS 2 and pain during needle penetration into prostate tissue and sampling was recorded as VAS 3.ResultsNo significant difference was found between the two groups with regard to age, body mass index, serum PSA, prostate volume and prostate cancer rates. Mean VAS-2 score was significantly lower in the PuNB group when compared with the PNB group. There was no significant difference in terms of VAS-1 and VAS-3 scores. There was no significant difference between the groups in terms of mild and severe complications.ConclusionsBoth techniques are safe for TRUS-guided prostate biopsy; however, PuNB provided more effective pain control compared to PNB especially during placement of rectal probe and manipulation.

A multicentre parallel-group randomised trial assessing multiparametric MRI characterisation and image-guided biopsy of prostate in men suspected of having prostate cancer: MULTIPROS study protocol

BackgroundThere is growing evidence suggesting that multiparametric magnetic resonance imaging (mpMRI) is a marker for prostate cancer (PCa) aggressiveness and could be used to plan treatment. Improving early detection of clinically significant PCa with pre-biopsy mpMRI would very likely have advantages including optimising the diagnosis and treatment of diseases and diminishing patient anxiety.Methods and materialsThis is a prospective multicentre study of pre-biopsy mpMRI diagnostic test accuracy with subgroup randomisation at a 1:1 ratio with respect to transrectal ultrasound (TRUS) and MRI/US fusion-guided biopsy or TRUS-only biopsy. It is designed as a single-gate study with a single set of inclusion criteria. The total duration of the recruitment phase was 48 months; however, this has now been extended to 66 months. A sample size of 600 participants is required.DiscussionThe primary objective is to determine whether mpMRI can improve PCa detection and characterisation. The key secondary objective is to determine whether MRI/US fusion-guided biopsy can reduce the number of false-negative biopsies. Ethical approval was obtained from the East of Scotland Research Ethics Committee 1 (14/ES/1070) on 20 November 2014. The results of this study will be used for publication and presentation in national and international journals and at scientific conferences.Trial registrationClinicalTrials.gov, NCT02745496. Retrospectively registered on 20 April 2016.

Отдаленные результаты первого опыта лечения мужчины с синдромом Мея–Тюрнера и варикозной болезнью вен органов малого таза

Recurrent and bilateral varicocele represent two least studied aspects of the disease. There is no recommendation in current urological and andrological guidelines in various countries on the diagnosis and treatment of such patients. The first experience of successful surgical treatment of a patient with recurrent varicocele due to May-Thurner syndrome is presented in this paper. The patient had a severe form of the disease and admitted with the varicocele recurrence after 5 previous intervention with chronic pelvic pain syndrome, erectile dysfunction, chronic calculous prostatitis and varicose veins of the pelvic organs. The patient underwent balloon angioplasty and stenting of the left iliac vein on 28th March, 2017 in the City hospital named after E.O. Mukhin. There was almost complete resolution of pelvic pain in the immediate postoperative period (within 1 hour). One week after surgery the patient noted a recovery of erection without any therapy. Three months later, a 45% reduction in the maximum diameter of the prostatic veins was noted according to transrectal ultrasound (TRUS) as well as a lack of antegrade blood flow according to the color Doppler TRUS at rest and during Valsalva's test. There was no deterioration of symptoms during follow-up. Overall, the venous blood flow in prostate was decreased which accompanied by the reducing in pain syndrome and restoration of sexual function without medical therapy. The reduction of diameter of testicular and epididymal varicose veins was seen 6 months after surgery. The diameter of veins of pampiniform plexus in supine position at rest was less than 2 mm. There was no retrograde flow neither in supine, nor in stand position during Valsalva maneuver. Thus, X-ray endovascular angioplasty and stenting of the iliac veins in case of arterio-venous crossing at the lower level is a pathogenetically justified and highly effective treatment of varicocele and varicose veins of the pelvic organs in men.

Addition of magnetic resonance imaging to real time trans-rectal ultrasound-based treatment planning for prostate implants.

PurposeThe greater soft tissue contrast of magnetic resonance imaging (MRI) allows improved accuracy in prostate contouring compared to transrectal ultrasound (TRUS) and helps in identifying specific regions within the prostate. This study attempts to evaluate the potential benefit of MRI-TRUS fusion in treatment planning for more accurate prostate contouring and tumor dose escalation.Material and methods14 patients with previous MRI-guided prostate biopsy and an low-dose-rate (LDR) permanent prostate seed implant have been selected. The prostate and tumor (5 patients) were contoured on the MRI images by a radiologist. The prostate was also contoured on TRUS images during LDR procedure together by a urologist and radiation oncologist. MRI and TRUS images were rigidly fused to compare prostate contours in MRI and TRUS. Prostate was then re-contoured by the radiation oncologist using this fusion. Moreover, V100, V150, and D90 differences were evaluated for localized tumor compared to prostate with negative values indicating cold tumor regions. These cases were re-planned to simulate dose escalation.ResultsThe prostate volume was contoured 8 ±10% smaller in TRUS images, compared to MRI images. The mean percent difference in tumor (compared to prostate) V100 was 0.3 ±–0.4%, V150 was –0.7 ±–24.8%, and D90 was 0.2 ±–12.1%. For the posteriorly located tumors (2 cases), V100 was 0.0 ±–0.3%, D90 was 9.5 ±–3.0%, and V150 was 26.1 ±–5.4%. For anteriorly located tumors (3 cases), V100 was 0.4 ±–0.4%, D90 was –6.0 ±–11.9%, and V150 was –18.5 ±–14.4% (became 15.6 ±14.6% after re-plan).ConclusionsThe MRI-TRUS image fusion is a feasible tool for the visualization of the prostate gland, particularly at the apex and base of the gland. Tumor identification presents the potential for dose escalation using fusion, especially for anteriorly located tumors.

MR imaging-guided prostate interventional imaging: Ready for a clinical use?

Prostate interventional magnetic resonance imaging (MRI) is now routinely performed in many centers. Its more widespread acceptance is limited by the cost of the use of MRI largely related to the long duration time of the procedures. However, the benefit of a robotic assistance has generated a new interest, because it substantially shortens the procedure time, while improving the accuracy. MRI-guided biopsy is considered as an appealing alternative to transrectal ultrasound (TRUS)-guided fusion biopsy, given the limitations of TRUS-MRI image registration systems. MRI-guided focal treatment also benefits from robotic assistance and from the unique property of MRI, which allows the measurement of the temperature in real-time during tumor ablation. The transrectal and transperineal approaches can be used and the respective indications of each pathway will depend on several factors, including the location of the tumor and the examination time, which will condition the occupation time of the MR room, a major factor influencing the overall cost of MRI-guided procedures. This review addresses the current practice of prostate MRI-guided interventional procedures and potential future applications.

Beyond transrectal ultrasound-guided prostate biopsies: available techniques and approaches.

Recent advances have led to the use of magnetic resonance imaging (MRI) alone or with fusion to transrectal ultrasound (TRUS) images for guiding biopsy of the prostate. Our group sought to develop consensus recommendations regarding MRI-guided prostate biopsy based on currently available literature and expert opinion. The published literature on the subject of MRI-guided prostate biopsy was reviewed using standard search terms and synthesized and analyzed by four different subgroups from among the authors. The literature was grouped into four categories-MRI-guided biopsy platforms, robotic MRI-TRUS fusion biopsy, template mapping biopsy and transrectal MRI-TRUS fusion biopsy. Consensus recommendations were developed using the Oxford Center for Evidence Based Medicine criteria. There is limited high level evidence available on the subject of MRI-guided prostate biopsy. MRI guidance with or without TRUS fusion can lead to fewer unnecessary biopsies, help identify high-risk (Gleason ≥ 3 + 4) cancers that might have been missed on standard TRUS biopsy and identify cancers in the anterior prostate. There is no apparent significant difference between MRI biopsy platforms. Template mapping biopsy is perhaps the most accurate method of assessing volume and grade of tumor but is accompanied by higher incidence of side effects compared to TRUS biopsy. Magnetic resonance imaging-guided biopsies are feasible and better than traditional ultrasound-guided biopsies for detecting high-risk prostate cancer and anterior lesions. Judicious use of MRI-guided biopsy could enhance diagnosis of clinically significant prostate cancer while limiting diagnosis of insignificant cancer.

Prostate Cancer Risk Assessment in Biopsy-naïve Patients: The Rotterdam Prostate Cancer Risk Calculator in Multiparametric Magnetic Resonance Imaging-Transrectal Ultrasound (TRUS) Fusion Biopsy and Systematic TRUS Biopsy

BackgroundThe value of multiparametric magnetic resonance imaging (mpMRI) and targeted biopsy (TBx) remains controversial for biopsy-naïve men when compared to transrectal ultrasound (TRUS)-guided systematic biopsy (SBx). Risk-based patient selection could help to selectively identify men with significant prostate cancer (PCa) and thus reduce unnecessary mpMRI and biopsies. ObjectivesTo compare PCa detection rates for mpMRI TBx with SBx and to determine the rate of potentially avoided mpMRI and biopsies through risk-based selection using the Rotterdam Prostate Cancer Risk Calculator (RPCRC). Design, setting, and participantsTwo-hundred consecutive biopsy-naïve men in two centres underwent mpMRI scanning, 12-core SBx, and subsequent MRI-TRUS TBx in the case of suspicious lesion(s) (Prostate Imaging-Reporting and Data System v.2 score ≥3). Outcome measurements and statistical analysisWe measured the detection rate for high-grade (Gleason score ≥ 3+4) PCa for TBx and SBx. We carried out a retrospective stratification according to RPCRC biopsy advice to determine the rate of mpMRI and biopsies that could potentially be avoided by RPCRC-based patient selection in relation to the rate of high-grade PCa missed. Results and limitationsTBx yielded high-grade PCa in 51 men (26%) and low-grade PCa in 14 men (7%), while SBx yielded high-grade PCa in 63 men (32%) and low-grade PCa in 41 men (21%). Four out of 73 men (5%) with negative RPCRC advice and 63 out of 127 men (50%) with positive advice had high-grade PCa. Upfront RPCRC-based patient selection for mpMRI and TBx would have avoided 73 out of 200 (37%) mpMRI scans, missing two out of 51 (4%) high-grade PCas. Limitations include the RPCRC definition of high- and low-grade PCa and different mpMRI techniques. ConclusionsmpMRI with TBx detected PCa with high Gleason score and avoided biopsy in low-grade PCa, but failed to detect all high-grade PCa when compared to SBx among biopsy-naïve men. Risk-based patient selection using the RPCRC can avoid one-third of mpMRI scans and SBx in biopsy-naïve men. Patient summaryMen with a suspicion of prostate cancer are increasingly undergoing a magnetic resonance imaging (MRI) scan. Although promising, MRI-targeted biopsy is not accurate enough to safely replace systematic prostate biopsy for now. Individualised assessment of prostate cancer risk using the Rotterdam Prostate Cancer Risk Calculator could avoid one-third of MRI scans and systematic prostate biopsies.

Validation of MRI to TRUS registration for high-dose-rate prostate brachytherapy

PurposeThe objective of this study was to develop and validate an open-source module for MRI to transrectal ultrasound (TRUS) registration to support tumor-targeted prostate brachytherapy. Methods and MaterialsIn this study, 15 patients with prostate cancer lesions visible on multiparametric MRI were selected for the validation. T2-weighted images with 1-mm isotropic voxel size and diffusion weighted images were acquired on a 1.5T Siemens imager. Three-dimensional (3D) TRUS images with 0.5-mm slice thickness were acquired. The investigated registration module was incorporated in the open-source 3D Slicer platform, which can compute rigid and deformable transformations. An extension of 3D Slicer, SlicerRT, allows import of and export to DICOM-RT formats. For validation, similarity indices, prostate volumes, and centroid positions were determined in addition to registration errors for common 3D points identified by an experienced radiation oncologist. ResultsThe average time to compute the registration was 35 ± 3 s. For the rigid and deformable registration, respectively, Dice similarity coefficients were 0.87 ± 0.05 and 0.93 ± 0.01 while the 95% Hausdorff distances were 4.2 ± 1.0 and 2.2 ± 0.3 mm. MRI volumes obtained after the rigid and deformable registration were not statistically different (p > 0.05) from reference TRUS volumes. For the rigid and deformable registration, respectively, 3D distance errors between reference and registered centroid positions were 2.1 ± 1.0 and 0.4 ± 0.1 mm while registration errors between common points were 3.5 ± 3.2 and 2.3 ± 1.1 mm. Deformable registration was found significantly better (p < 0.05) than rigid registration for all parameters. ConclusionsAn open-source MRI to TRUS registration platform was validated for integration in the brachytherapy workflow.

Dosimetry of permanent interstitial prostate brachytherapy for an interoperative procedure, using O-arm based CT and TRUS

PurposeThe aim of this report is dosimetric evaluation for an intraoperative fusion computed tomography (CT) as a superior predictor of 1-month CT based dosimetry in comparison to transrectal ultrasound (TRUS) in permanent interstitial prostate brachytherapy.Material and methodsData of 65 patients treated with seed implantation were analyzed. All procedures has been performed with patients in the lithotomy position inside the O-arm system. An end-fine probe is used as a landmark to fuse TRUS and O-arm-based CT images. There was no difference in the patient's position, probe position, and timing of image acquisition between the two imaging modalities. Dose-volume histogram (DVH) parameters such as the dose to 90% of prostate volume (D90) has been analyzed.ResultsThe area under the curve of the receiver operating characteristic tended to be larger on fusion CT than on TRUS for most DVH parameters (71.85% vs. 59.59% for D90; p = 0.07). Significant relationships between fusion CT and 1-month CT were confirmed using Pearson's correlation coefficients for most DVH parameters (R = 0.48, p < 0.01 for D90), although the relationship between TRUS and 1-month CT was poor. Large dose reduction (35 Gy for D90) was seen from TRUS to fusion CT, especially in patients with high body weight and small prostate volume.ConclusionsIntraoperative fusion CT appears to have higher predictive power for 1-month CT-based dosimetry than TRUS. A prospective trial using fusion CT-based planning is warranted.

Population-based prediction of subject-specific prostate deformation for MR-to-ultrasound image registration.

Statistical shape models of soft-tissue organ motion provide a useful means of imposing physical constraints on the displacements allowed during non-rigid image registration, and can be especially useful when registering sparse and/or noisy image data. In this paper, we describe a method for generating a subject-specific statistical shape model that captures prostate deformation for a new subject given independent population data on organ shape and deformation obtained from magnetic resonance (MR) images and biomechanical modelling of tissue deformation due to transrectal ultrasound (TRUS) probe pressure. The characteristics of the models generated using this method are compared with corresponding models based on training data generated directly from subject-specific biomechanical simulations using a leave-one-out cross validation. The accuracy of registering MR and TRUS images of the prostate using the new prostate models was then estimated and compared with published results obtained in our earlier research. No statistically significant difference was found between the specificity and generalisation ability of prostate shape models generated using the two approaches. Furthermore, no statistically significant difference was found between the landmark-based target registration errors (TREs) following registration using different models, with a median (95th percentile) TRE of 2.40 (6.19) mm versus 2.42 (7.15) mm using models generated with the new method versus a model built directly from patient-specific biomechanical simulation data, respectively (N = 800; 8 patient datasets; 100 registrations per patient). We conclude that the proposed method provides a computationally efficient and clinically practical alternative to existing complex methods for modelling and predicting subject-specific prostate deformation, such as biomechanical simulations, for new subjects. The method may also prove useful for generating shape models for other organs, for example, where only limited shape training data from dynamic imaging is available.

One-stop prostate imaging: multiparametric-MRI followed by TRUS-guided biopsy

Purpose The current role of prostate cancer imaging is to provide biopsy guidance and staging. Previously, magnetic resonance imaging (MRI) was used to pre-assess patients for radical therapy. Recently, multiparametric MRI (MP-MRI) has helped transform the diagnostic pathway through an improved yield in detecting and characterising cancer and is used prior to biopsy in many centres. At our centre, we have recently provided a one-stop same day service of MP-MRI to transrectal ultrasound (TRUS) for pre-selected patients. We investigate whether this service leads to a reduced time to management outcome. Methods and materials Three groups of 20 consecutive patients were identified: TRUS biopsy followed by staging MRI, MP-MRI after TRUS biopsy and the one-stop MP-MRI/TRUS biopsy patients. Date of referral to management outcome decision date was recorded from multi-disciplinary teams (MDT) and clinic letters. Results The mean days of referral to outcome is 75.0, 66.2 and 30.1 days for the TRUS biopsy followed by staging MRI, MP-MRI after TRUS biopsy and one-stop MP-MRI/TRUS biopsy respectively, with the latter group showing less variability. Conclusion A one-stop prostate imaging service in pre-selected patients allows localised staging prior to biopsy, identifies suspicious areas for a targeted biopsy, avoids the pitfalls of post biopsy artefact in MRI interpretation, expedites the MDT process and enhances patient experience. The current role of prostate cancer imaging is to provide biopsy guidance and staging. Previously, magnetic resonance imaging (MRI) was used to pre-assess patients for radical therapy. Recently, multiparametric MRI (MP-MRI) has helped transform the diagnostic pathway through an improved yield in detecting and characterising cancer and is used prior to biopsy in many centres. At our centre, we have recently provided a one-stop same day service of MP-MRI to transrectal ultrasound (TRUS) for pre-selected patients. We investigate whether this service leads to a reduced time to management outcome. Three groups of 20 consecutive patients were identified: TRUS biopsy followed by staging MRI, MP-MRI after TRUS biopsy and the one-stop MP-MRI/TRUS biopsy patients. Date of referral to management outcome decision date was recorded from multi-disciplinary teams (MDT) and clinic letters. The mean days of referral to outcome is 75.0, 66.2 and 30.1 days for the TRUS biopsy followed by staging MRI, MP-MRI after TRUS biopsy and one-stop MP-MRI/TRUS biopsy respectively, with the latter group showing less variability. A one-stop prostate imaging service in pre-selected patients allows localised staging prior to biopsy, identifies suspicious areas for a targeted biopsy, avoids the pitfalls of post biopsy artefact in MRI interpretation, expedites the MDT process and enhances patient experience.