Robotic assisted laparoscopic prostatectomy in a patient with prostate cancer and complex urinary tract malformation.

We present a case of prostate cancer with abnormal renal and ureteric anatomy who underwent robotic assisted laparoscopic prostatectomy. This is a 59-year-old European patient who presented with lower urinary tract symptoms (LUTS) and pelvic pain. Investigations revealed prostate cancer as well as a supernumerary right kidney and an atrophic horseshoe left kidney draining into the left seminal vesicle. He was managed with robotic assisted laparoscopic prostatectomy (RALP) using a modified technique. Selective pre-operative investigations and patient counselling led to proper operative planning and good surgical technique and outcome.

Laparoscopic heminephrectomy for duplex system: observed difference in outcomes between upper and lower pole resections.

INTRODUCTION: Renal duplication is a relatively common congenital abnormality of the urinary tract, but symptomatic duplex kidney is a rare presentation in adults. Traditionally, the treatment of choice for poorly functioning moiety has been heminephrectomy. There is extensive literature detailing the outcomes of minimally invasive upper pole heminephrectomy, but comparatively little published regarding lower pole resection, especially in adult patients. We present a series of 13 patients who underwent minimally invasive heminephrectomy for duplex kidney. MATERIALS AND METHODS: Over a 6 year period (2011-2017) 13 patients at a single center underwent laparoscopic heminephrectomy for symptomatic duplex kidney with a poorly functioning moiety. A retrospective review of case notes and imaging was undertaken. RESULTS: Eight and 5 patients underwent upper and lower pole heminephrectomies, respectively. Laparoscopic transperitoneal approach was utilized in all cases. Median length of stay was 2 days (range 1 to 16 days). In the upper pole cohort, one patient had a postoperative infection requiring IV antibiotics. In the lower pole cohort by contrast, there were three major complications (60%). Conversion to complete nephrectomy was necessary in one case; one patient had urinary leakage requiring selective embolization and one patient required a second operation to resect remnant calyces. Furthermore, two patients (40%) developed late recurrence of symptoms. CONCLUSIONS: Symptomatic duplex kidney is a rare presentation in adults. In our experience, heminephrectomy for non-functioning renal unit is safe and reproducible in experienced hands with no major complications and resolution of symptoms in the majority of patients. We have, however, observed a higher complication rate in those undergoing resection of a lower pole moiety. Alternative management such as uretero-ureterostomy should be considered in these cases.

Zone-specific logistic regression models improve classification of prostate cancer on multi-parametric MRI.

OBJECTIVES: To assess the interchangeability of zone-specific (peripheral-zone (PZ) and transition-zone (TZ)) multiparametric-MRI (mp-MRI) logistic-regression (LR) models for classification of prostate cancer. METHODS: Two hundred and thirty-one patients (70 TZ training-cohort; 76 PZ training-cohort; 85 TZ temporal validation-cohort) underwent mp-MRI and transperineal-template-prostate-mapping biopsy. PZ and TZ uni/multi-variate mp-MRI LR-models for classification of significant cancer (any cancer-core-length (CCL) with Gleason > 3 + 3 or any grade with CCL ≥ 4 mm) were derived from the respective cohorts and validated within the same zone by leave-one-out analysis. Inter-zonal performance was tested by applying TZ models to the PZ training-cohort and vice-versa. Classification performance of TZ models for TZ cancer was further assessed in the TZ validation-cohort. ROC area-under-curve (ROC-AUC) analysis was used to compare models. RESULTS: The univariate parameters with the best classification performance were the normalised T2 signal (T2nSI) within the TZ (ROC-AUC = 0.77) and normalized early contrast-enhanced T1 signal (DCE-nSI) within the PZ (ROC-AUC = 0.79). Performance was not significantly improved by bi-variate/tri-variate modelling. PZ models that contained DCE-nSI performed poorly in classification of TZ cancer. The TZ model based solely on maximum-enhancement poorly classified PZ cancer. CONCLUSION: LR-models dependent on DCE-MRI parameters alone are not interchangable between prostatic zones; however, models based exclusively on T2 and/or ADC are more robust for inter-zonal application. KEY POINTS: • The ADC and T2-nSI of benign/cancer PZ are higher than benign/cancer TZ. • DCE parameters are significantly different between benign PZ and TZ, but not between cancerous PZ and TZ. • Diagnostic models containing contrast enhancement parameters have reduced performance when applied across zones.

Logistic regression model for diagnosis of transition zone prostate cancer on multi-parametric MRI.

OBJECTIVES: We aimed to develop logistic regression (LR) models for classifying prostate cancer within the transition zone on multi-parametric magnetic resonance imaging (mp-MRI). METHODS: One hundred and fifty-five patients (training cohort, 70 patients; temporal validation cohort, 85 patients) underwent mp-MRI and transperineal-template-prostate-mapping (TPM) biopsy. Positive cores were classified by cancer definitions: (1) any-cancer; (2) definition-1 [≥Gleason 4 + 3 or ≥ 6 mm cancer core length (CCL)] [high risk significant]; and (3) definition-2 (≥Gleason 3 + 4 or ≥ 4 mm CCL) cancer [intermediate-high risk significant]. For each, logistic-regression mp-MRI models were derived from the training cohort and validated internally and with the temporal cohort. Sensitivity/specificity and the area under the receiver operating characteristic (ROC-AUC) curve were calculated. LR model performance was compared to radiologists' performance. RESULTS: Twenty-eight of 70 patients from the training cohort, and 25/85 patients from the temporal validation cohort had significant cancer on TPM. The ROC-AUC of the LR model for classification of cancer was 0.73/0.67 at internal/temporal validation. The radiologist A/B ROC-AUC was 0.65/0.74 (temporal cohort). For patients scored by radiologists as Prostate Imaging Reporting and Data System (Pi-RADS) score 3, sensitivity/specificity of radiologist A 'best guess' and LR model was 0.14/0.54 and 0.71/0.61, respectively; and radiologist B 'best guess' and LR model was 0.40/0.34 and 0.50/0.76, respectively. CONCLUSIONS: LR models can improve classification of Pi-RADS score 3 lesions similar to experienced radiologists. KEY POINTS: • MRI helps find prostate cancer in the anterior of the gland • Logistic regression models based on mp-MRI can classify prostate cancer • Computers can help confirm cancer in areas doctors are uncertain about.

Can multiparametric magnetic resonance imaging predict upgrading of transrectal ultrasound biopsy results at more definitive histology?

OBJECTIVE: To determine whether multiparametric magnetic resonance imaging (mp-MRI) has a role in reducing the uncertainty in risk stratification by transrectal ultrasound (TRUS) biopsy, using histology at transperineal template-guided prostate mapping (TPM) biopsy as the reference test. MATERIALS AND METHODS: Overall, 194 patients underwent TRUS biopsy, who were followed up in less than 18 months by means of (a) mp-MRI with pelvic phased array using T2-weighted, diffusion-weighted and dynamic contrast-enhanced sequences and (b) TPM biopsy. Of those patients, low risk on TRUS biopsy was defined in 4 different ways--(a) definition 1: Gleason 3+3 (any cancer core length) (n = 137), (b) definition 2: maximum cancer core length (MCCL)<50% (any Gleason score) (n = 62), (c) definition 3: Gleason 3+3 and MCCL<50% (n = 52), and (d) definition 4: Gleason 3+3, MCCL<50%, prostate-specific antigen level<10 ng/ml, and<50% positive cores (n = 28). Mp-MRI was scored for the likelihood of cancer from 1 (cancer very unlikely) to 5 (cancer very likely). Binary logistic regression analysis was performed to evaluate the association between MRI scores and TPM histology. RESULTS: Median prostate-specific antigen level was 7 ng/ml (range: 0.9-29), median time between TRUS biopsy and mp-MRI was 120 days (range: 41-480), and median time between mp-MRI and TPM biopsy was 60 days (range: 1-420). A median of 48 cores (range: 20-118) were taken at TPM biopsy. Gleason score was upgraded in 62 of 137 (45%) patients at TPM biopsy. The negative predictive values of mp-MRI score 1 to 2 for predicting that cancer remained low risk (according to each definition) were 75%, 100%, 83%, and 100% for definitions 1, 2, 3, and 4, respectively. An mp-MRI score of 4 to 5 had positive predictive values for upgrade or upsize of 59%, 67%, 75%, and 69% for definitions 1, 2, 3, and 4, respectively. CONCLUSION: The presence of an mp-MRI lesion in men with low-risk prostate cancer on TRUS biopsy confers, in most patients, a high likelihood that higher-risk disease will be present (either Gleason pattern 4 or a significant cancer burden). Conversely, if a lesion is not seen on mp-MRI, the attribution of low-risk grade or cancer burden is much more likely to be correct. Mp-MRI might therefore be used to triage men for resampling biopsies before entering active surveillance.

The accuracy of multiparametric MRI in men with negative biopsy and elevated PSA level--can it rule out clinically significant prostate cancer?

PURPOSE: To assess the performance of multiparametric magnetic resonance imaging (mp-MRI) in patients with previous negative transrectal ultrasound (TRUS) guided prostate biopsy. MATERIALS AND METHODS: Fifty-four patients with at least 1 previous negative TRUS prostate biopsy underwent mp-MRI in the form of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging. This was followed by transperineal template systematic prostate biopsies. Analysis was done based on 2 sectors per prostate, right and left (108 sectors out of 54 prostates). mp-MRI was scored using an ordinal scale 1 to 5 based on the suspicion of the presence of clinically significant disease. We used 6 different definitions for clinically significant disease and tested the performance of mp-MRI at each single definition. RESULTS: Median age was 64 (range, 39-75), median PSA level was 10 (range, 2-23), and median number of biopsies was 45 (range, 21-137). Cancer of any volume and any grade was detected in 34 of 54 (63%) patients. mp-MRI accuracy at detection of clinically significant cancer using University College London (UCL) definition 2 (any Gleason score of 4 or maximum cancer core length of ≥ 4 mm or both) showed sensitivity of 76%, specificity of 42%, positive predictive value of 38%, and negative predictive value of 79%. For a different definition of significant tumor (UCL definition 1; dominant Gleason score 4 or maximum cancer core length ≥ 6 mm or both), the sensitivity was 90%, specificity 42%, positive predictive value 26%, and negative predictive value 95%. CONCLUSIONS: mp-MRI showed good performance at both detection and ruling out clinically significant disease, according to the definition used. mp-MRI can then be used as a triage test in the population with persistently elevated or rising PSA levels to select patients that can avoid unnecessary prostate biopsy.

Transperineal magnetic resonance image targeted prostate biopsy versus transperineal template prostate biopsy in the detection of clinically significant prostate cancer.

PURPOSE: Multiparametric magnetic resonance imaging can be used to guide prostate biopsy by targeting biopsies to areas in the prostate at high risk for cancer. We compared the detection of clinically significant and insignificant cancer by transperineal magnetic resonance imaging targeted biopsy and transperineal template guided prostate biopsy. MATERIALS AND METHODS: A total of 182 men with a lesion suspicious for cancer on multiparametric magnetic resonance imaging underwent transperineal magnetic resonance imaging targeted biopsy using a cognitive registration technique, followed by systematic transperineal template guided prostate biopsy. The primary outcome was the detection rate of clinically significant prostate cancer. Clinical significance was defined using maximum cancer core length 4 mm or greater and/or Gleason grade 3 + 4 or greater (University College London definition 2). We secondarily evaluated other commonly used thresholds of clinically significant disease, including maximum cancer core length 6 mm or greater and/or Gleason grade 4 + 3 or greater, maximum cancer core length 3 mm or greater and/or Gleason grade 3 + 4 or greater, and maximum cancer core length 2 or greater mm and/or Gleason grade 3 + 4 or greater. Strategies were statistically compared with the McNemar test. RESULTS: Mean ± SD patient age was 63.3 ± 7.2 years. Median prostate specific antigen was 6.7 ng/ml (IQR 4.7-10.0). Clinically significant cancer was detected by magnetic resonance imaging targeted biopsy and template guided prostate biopsy in 103 (57%) and 113 of the 182 men (62%) (p = 0.174), and clinically insignificant cancer was detected in 17 (9.3%) and 31 (17.0%), respectively (p = 0.024). CONCLUSIONS: Prostate biopsy targeted to suspicious lesions on multiparametric magnetic resonance imaging has encouraging rates of detection of clinically significant cancer while also decreasing the detection rate of clinically insignificant cancer. This is achieved with fewer biopsy cores than for systematic template guided biopsy. Further prospective, multicenter, comparative trials of the performance of targeting strategies are needed to consider magnetic resonance imaging targeted biopsy an alternative to conventional systematic biopsy.