Clinical impact of Prostate-Specific Membrane Antigen Positron Emission Tomography (PET) on intensification or deintensification of advanced renal cell carcinoma management.

PURPOSE: There is an emerging role of the use of Prostate-Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) in renal cell carcinoma. Herein, we report our experience in use of PSMA PET in recurrent or metastatic renal cell carcinoma (RCC). METHODS: A retrospective analysis of all patients who underwent PSMA PET for suspected recurrent or de-novo metastatic RCC between 2015 and 2020 at three institutions was performed. The primary outcome was change in management (intensification or de-intensification) following PSMA PET scan. Secondary outcomes included histopathological correlation of PSMA avid sites, comparison of sites of disease on PSMA PET to diagnostic CT and time to systemic treatment.

Outcomes of post-chemotherapy robot-assisted retroperitoneal lymph node dissection in testicular cancer: multi-institutional study.

OBJECTIVE: To evaluate the perioperative and oncological outcomes after post-chemotherapy robot-assisted retroperitoneal lymph node dissection (PC-RARPLND). MATERIALS AND METHODS: We retrospectively reported the perioperative and oncological outcomes of all the patients with testicular cancer who underwent PC-RARPLND at three tertiary teaching centers. Descriptive statistical measures were used to report demographic, clinical, intraoperative, postoperative and oncological outcomes. RESULTS: There were 43 consecutive patients who underwent PC-RARPLND at the participating institutions. Mean patient age was 29.2 years (± 8.2), BMI was 26.6 kg/m2 (± 6.2). The mean size of retroperitoneal mass was 4.1 cm (± 3.5). Full bilateral template dissection was performed in 38 (88.3%) patients. Nerve sparing was attempted in 19 (44.1%) patients. Mean operative time was 374 min (± 132) and estimated blood loss was 292 ml (± 445.6). The mean postoperative LOS was 2.8 days (± 5.9). There was a total of 12 complications in 10 patients (Clavien grade I = 5, II = 3, III = 3 and IV = 1). Postoperative pathology demonstrated 24 patients (55%) with necrosis/fibrosis, 16 (37%) with teratoma and 3 (7%) with viable tumor. Mean lymph node (LN) yield was 26.5 LNs (SD ± 16.1). Patients were followed for a mean of 30.7 months (± 24.7). No deaths were documented during follow-up and 2 pulmonary recurrences were identified. Antegrade ejaculation was preserved in 70.6% of patient who underwent nerve sparing. Limitations included retrospective nature and limited follow up. CONCLUSION: PC-RAPLND is safe and technically reproducible. It provides improved morbidity and less convalescence.

Holmium laser enucleation of the prostate for very large benign prostatic hyperplasia (≥ 200 cc).

PURPOSE: Patients presenting with prostate gland sizes greater than 200 cc pose a unique surgical challenge to both patients and surgeons. The objective of this study is to critically assess the efficacy and risks associated with performing holmium laser enucleation of the prostate (HoLEP) on glands ≥ 200 cc. MATERIALS AND METHODS: Using a prospective maintained database, all consecutive benign prostatic hyperplasia (BPH) patients with gland size ≥ 200 cc who underwent HoLEP were included. We reported patient preoperative, intraoperative, postoperative outcomes and complications. Subgroup analysis of outcomes was stratified by gland sizes 200-299 cc and ≥ 300 cc. Univariate analysis using Kruskal-Wallis and Fisher exact test was performed to compare the two groups. RESULTS: There were 88 patients with a mean preoperative gland size of 255.9 cc (200-770 cc). Mean operative (171 vs 182 min) and enucleation time (77 vs 83 min) were not different between the two subgroups (200-299 cc vs ≥ 300 cc). Enucleation efficiency was greater for glands ≥ 300 cc (2.6 cc/min vs 2.0 cc/min, p = 0.04). Morcellation time was longer in the ≥ 300 cc group (74.5 min vs 46.8 min, p = 0.021). Mean length of stay was 1.8 ± 1.2 days and catheter duration was 2.6 ± 2.7 days. 1 (1.1%) patient required retreatment of BPH at last follow-up. The main limitation of this study is the retrospective data analysis. CONCLUSIONS: Holmium laser enucleation for prostate glands volume > 200 cc is feasible with minimal morbidity. These data further reinforce the size independence success of this procedure for BPH.

Effect of intracorporeal urinary diversion on the incidence of benign ureteroenteric stricture after cystectomy.

OBJECTIVES: To compare ureteroenteric stricture rates after radical cystectomy in patients who undergo an intracorporeal urinary diversion versus other surgical approaches. METHODS: We retrospectively reviewed health records of all patients who underwent cystectomy with urinary diversion at Mayo Clinic Hospital (Phoenix, AZ, USA) from 1 January 2007 through 1 January 2018. Ureteroenteric stricture was identified by surveillance imaging. Patients were stratified by surgical approach: open radical cystectomy, robot-assisted radical cystectomy with extracorporeal urinary diversion and robot-assisted radical cystectomy-intracorporeal urinary diversion. A Cox proportional hazards model was fitted that included independent predictors of stricture development. RESULTS: Of the 573 cystectomies assessed, 236 (41.2%) were carried out robotically. In the robot-assisted radical cystectomy cohort, 39 patients (16.5%) underwent intracorporeal urinary diversion. The median follow-up period was 55, 70 and 71 months for the open radical cystectomy, robot-assisted radical cystectomy-extracorporeal urinary diversion and robot-assisted radical cystectomy-intracorporeal urinary diversion groups, respectively. Subgroup stricture rates were as follows: open radical cystectomy, 8.0%; robot-assisted radical cystectomy-extracorporeal urinary diversion, 9.6%; and robot-assisted radical cystectomy-intracorporeal urinary diversion, 2.6% (P = 0.33). The median time to stricture was 5 months (interquartile range 3.3-11.5 months). In the bivariable analysis, factors that were associated with the development of ureteroenteric stricture were postoperative urinary leak (hazard ratio 3.177, 95% confidence interval 1.129-8.935; P = 0.03) and body mass index (hazard ratio 1.078, 95% confidence interval 1.027-1.132; P = 0.002). On multivariable logistic regression analysis, intracorporeal urinary diversion approach was not associated with the development of ureteroenteric stricture (hazard ratio 0.272, 95% confidence interval 0.036-2.066; P = 0.21). CONCLUSIONS: Ureteroenteric stricture is a complication that typically occurs within the first postoperative year. Although our results did not support major differences in outcomes between intracorporeal urinary diversion and extracorporeal urinary diversion, the small sample size did not exclude the possibility of a type 2 statistical error.

Feasibility of holmium laser enucleation of the prostate as a 1-day surgery.

PURPOSE: To assess the safety and feasibility of HoLEP as a day-case procedure. METHODS: We reviewed all consecutive patients who underwent HoLEP at our institution between February 2017 and March 2018. During this time, we began a prospective trial aimed at same-day discharge of specific patients. Baseline and demographic variables, and past medical, past urological, intra-operative and post-operative variables in addition to disposition and readmission data were collected. Bivariate analysis was conducted to compare patients based on the day of discharge and readmission. A multivariable model using multiple-regression analysis was used to assess predictors for early discharge or readmission. RESULTS: There were 179 total HoLEP procedures that were performed during the study period. Forty-seven patients were suitable candidates for same-day discharge. Among this group, 28 (59.5%) patients were successfully discharged home on the same day. Nineteen patients (40.4%) could not be discharged. The most common cause of not to discharge patients was the degree of hematuria without continuous bladder irrigation. Pre-operative prostate volume was different between the two groups (88.4 ± 30.7 cc for discharged patients vs 69.0 ± 30.7 cc for admitted patients, p = 0.033). No other pre-operative differences were identified. There were five readmissions (17.8%) following same-day discharge. Readmitted patients had higher rates of history of urinary tract infection (80% vs 26.2%, p = 0.0304). On multivariable analysis, no statistically significant predictors were identified for early discharge or readmission. CONCLUSIONS: Same-day discharge following HoLEP is safe and feasible in well-selected patients.

Role of robot-assisted retroperitoneal lymph node dissection in malignant mesothelioma of the tunica vaginalis: case series and review of the literature.

INTRODUCTION: The management of malignant mesothelioma of the tunica vaginalis (MMTVT) is not clearly defined. Retroperitoneal lymph node dissection has been reported as a potential management option. Herein we present our experience with robot-assisted retroperitoneal lymph node dissection (RARPLND) in our series of patients with MMTVT. MATERIALS AND METHODS: The Mayo Clinic cancer registry was queried from 1972-present for all patients who had a diagnosis of MMTVT. Six patients were identified, five of whom were treated with RPLND, where four underwent RARPLND. RESULTS: In five patients who underwent RPLND, the median age was 50 years (IQR 34-51). Four patients originally presented with right sided symptomatic hydroceles, while one presented with right sided chronic epididymitis. Orchiectomy (one simple, two inguinal radical) was performed in three patients prior to presentation. Preoperative cross-sectional imaging, including PET-CT scan in three patients, was negative for lymphadenopathy or metastasis. RARPLND was performed in 4/5 (80%) cases and concomitant hemiscrotectomy in 4/5 (80%) cases. Full bilateral template was performed in three patients and right modified template was performed in the remaining two. Median lymph node yield was 29 (IQR 22-32) and median blood loss was 275 cc (IQR 200-300). Positive retroperitoneal lymph nodes were found in 3/5 (60%) cases. All patients who underwent RARPLND were discharged home on postoperative day one. Mean follow up was 27 months (range 3-47). No patients recurred. CONCLUSIONS: Regardless of the approach, RPLND may provide a diagnostic benefit in patients who present with MMTVT, with the robotic approach affording a potentially expedited recovery.

The Role of Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography in Primary Staging of Selected Renal Tumours: Initial Experience in a Multicentre Cohort.

BACKGROUND: Accurate primary staging of renal cancer with conventional imaging is challenging. Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) may serve to improve the accuracy of renal cancer staging. OBJECTIVE: To determine clinicopathological and management differences for primary renal cancer staged with PSMA PET/CT in comparison to conventional imaging. DESIGN, SETTING, AND PARTICIPANTS: We conducted a retrospective cohort study of PSMA PET/CT scans performed for primary staging of renal cancer and incidental renal lesions at three sites in Brisbane, Australia between June 2015 and June 2020. Clinical characteristics, imaging, and histopathology were reviewed. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Clinicopathological and management differences according to staging modality (PSMA PET/CT, conventional imaging) were assessed. Descriptive statistics were used to report demographics and clinical parameters. Nonparametric methods were used for statistical analysis. Fisher's exact test was used for comparison of small-cell size categorical variables. RESULTS AND LIMITATIONS: From a total of 120 PSMA PET/CT scans, 61 were included (52 staging, 9 incidental) for predominantly males (74%) with a mean age of 65.1 yr (standard deviation 12.0). Most primary lesions (40/51) were clear-cell renal cell carcinoma (ccRCC; 98% PSMA-avid), eight were non-ccRCC (75% PSMA-avid), and three were non-RCC (oncocytoma; 67% PSMA-avid). PSMA PET identified a greater number of presumed metastatic lesions than conventional imaging (195 vs 160). A management change was observed for 32% of patients (20% major, 12% minor). Limitations include the retrospective design and selection bias, lack of blinding to PSMA reporting, and the use of different PSMA radiotracers. CONCLUSIONS: PSMA PET/CT detected more metastases than conventional imaging and most renal cancers were PSMA-avid, resulting in a management change for one-third of the patients. PATIENT SUMMARY: We looked at a newer type of scan called PSMA PET/CT for first staging of kidney cancer. We found that this detects more metastasis and helps in decisions on changes in treatment for some patients. This type of imaging is a useful addition to conventional scans in tricky cases and may help in better selection of suitable treatments, but more studies are required.

Uro-symphyseal Fistula: A Systematic Review to Inform a Contemporary, Evidence-based Management Framework.

OBJECTIVE: To collate available data via systematic review considering etiology, presentation, and treatment of Uro-Symphyseal Fistula (USF) in order to inform a contemporary management framework. MATERIALS AND METHODS: A systematic review was performed according to the Cochrane Handbook and registered in PROSPERO (CRD42021232954). MEDLINE and CENTRAL databases were searched for manuscripts considering USF published between 2000 and 2022. Full text manuscripts were reviewed for clinical data. Univariate statistical analysis was performed where possible. RESULTS: A total of 31 manuscripts, comprising 248 USF cases, met inclusion criteria. Suprapubic pain and difficulty ambulating were common symptoms. MRI confirmed the diagnosis in 95% of cases. Radiotherapy for prostate cancer was the most common predisposing factor (93%). Among these patients, prior endoscopic bladder outlet surgery was common (83%; bladder neck incision/urethral dilatation n = 59, TURP/GLL PVP n = 34). In those with prior prostatic radiation, conservative management failed in 96% of cases. Cystectomy with urinary diversion (86% n = 184) was favored over bladder-sparing techniques (14% (n = 30) after prior radiation. In radiation naïve patients, conservative management failed in 72% of patients, resulting in either open fistula repair with flap (62%) or radical prostatectomy (28%). CONCLUSION: Prior radiotherapy is a significant risk factor for USF and almost always requires definitive major surgery (debridement, cystectomy, and urinary diversion). On the basis of the findings within this systematic review, we present management principles that may assist clinicians with these complex cases. Further research into pathogenesis, prevention, and optimal treatment approach is required.

Characterization of tumor thrombus in renal cell carcinoma with prostate specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT).

INTRODUCTION: Venous tumor thrombus (TT) occurs as part of the natural history of renal cell carcinoma (RCC) local progression in a small minority of cases. MRI is currently the most accurate imaging modality for determining TT extent. PSMA PET/CT may improve RCC staging and IVC TT characterization. The objective of this study was to investigate the role of PSMA PET/CT in defining superior extent of TT in RCC and TT IVC tributary vessel spread, with comparative accuracy vs. MRI, to assess suitability for resection and inform preoperative surgical planning. METHODS: Patients who underwent PSMA PET/CT for assessment of renal malignancy with TT from 2015 to 2020 at 3 tertiary hospitals in Brisbane, Australia, were retrospectively identified. TT extent was classified using Mayo Clinic levels and compared according to imaging modality. RESULTS: Fourteen patients were included, all of which were clear cell RCC. Ten patients also underwent MRI, 6 of which were concordant in extent according to MRI and PSMA PET. Discordant extent occurred in 4 patients, of which 2 patients had non-PSMA avid thrombus (Mayo level 0 and level 3 on MRI). Further discordance was seen in a patient with adrenal vein and lumbar vein TT only seen on MRI and PSMA PET/CT, respectively. Finally, discordant extent was seen in another patient with Mayo level 4 TT without lumbar vein involvement on MRI vs. level 3 on PSMA PET/CT with lumbar vein involvement. CONCLUSIONS: PSMA PET/CT can provide additional information about TT extent in RCC which may not be seen on MRI. Additional information from PSMA PET/CT in this setting may assist surgical planning, in addition to detection of metastatic disease.

The role of dual tracer PSMA and FDG PET/CT in renal cell carcinoma (RCC) compared to conventional imaging: A multi-institutional case series with intra-individual comparison.

PURPOSE: The objective of this study was to perform an intra-individual dual tracer comparison of Fluorodeoxyglucose (FDG) and Prostate Specific Membrane Antigen (PSMA) computed tomography (CT)/Positron Emission Tomography (PET) against standard of care (SOC) imaging for the characterisation, staging and restaging of renal cell carcinoma (RCC). METHODS: A multicentre retrospective cohort study was performed at 3 major tertiary referral institutions in Brisbane, Australia between 2015 and 2020. All patients who underwent both PSMA and FDG PET/CT following SOC imaging for investigation of RCC were identified. Clinical details, imaging characteristics and histopathology were collected prior to univariate statistical analysis. RESULTS: Eleven patients who underwent dual tracer PET/CT were included. Mean age was 65.5 years (SD 8.8). Most patients were male (64%) with clear cell morphology (91%). The indication for dual tracer PET was staging (36%) and restaging after radical/partial nephrectomy (64%). Primary tumour assessment showed mixed avidity patterns (concordant 40%, discordant favouring PSMA 20%, and FDG 40%). Metastatic disease assessment showed concordant avidity in 6 patients (55%), concordant negative in 3 (27%), and discordant uptake favouring PSMA. PET outperformed SOC imaging for assessment of metastatic disease in 5 patients (45%) and equivalent for the remainder. A change in management was noted in three cases (27%). CONCLUSION: Dual tracer FDG and PSMA PET/CT for assessment of primary and metastatic RCC were mostly concordant. PET imaging outperformed conventional imaging and led to a change in management for 1 in 4 patients. Further studies with larger samples sizes are required to validate these findings and identify characteristics to guide patient selection for selective or dual tracer use.

Can artificial urinary sphincter be an effective salvage option in women following failed anti-incontinence surgery?

INTRODUCTION AND HYPOTHESIS: The role of artificial urinary sphincter (AUS) as salvage option following failed anti-incontinence surgery is unclear. METHODS: Database review and telephone survey were conducted to review patient satisfaction, surgical outcomes, device failure and revision rates. RESULTS: A total of 29 female patients received AUS following failed anti-incontinence surgeries. Five (17%) AUS devices were explanted due to AUS erosion or infection. Thirteen AUS revisions were made and device malfunction accounted for 95% of the cases. Kaplan-Meier analysis showed more than 90% of AUS malfunction occurred less than 100 months from the time of implant. There was a significant decrease in pad use (3.6 to 0.2 pads per day; p < 0.01). The continence rate with no pad use was 70% and this increases to 83% in patients wearing one precautionary pad. CONCLUSION: AUS is a safe, durable and effective salvage option for females with previous failed anti-incontinent surgeries.

Use of treatment pathway improves neoadjuvant chemotherapy use in muscle-invasive bladder cancer.

PURPOSE: To assess the trends of neoadjuvant chemotherapy (NAC) use since its introduction in our practice pathway in patients with cT2 + bladder cancer over a 20-year period. METHODS: This is a retrospective review of patients with cT2 + bladder cancer who underwent RC between 01/01/1998 and 01/01/2018 that aimed to evaluate the trends of NAC use and associated after implementation of a multidisciplinary treatment pathway. Cohorts were stratified into eras: pre-NAC (1998-2007) to NAC eras (2008-2018). Univariate analysis was conducted using Chi-squared test and Kaplan-Meier estimates were used to evaluate survival. RESULTS: In 904 total patients who underwent RC, there were 493 with cT2 + UCC disease. The rate of NAC peaked at 84.2% in the most recent year of analysis in all patients and was 100% in cT2 + patients eligible for NAC. There was an increased rate of complete response (downstage to pT0) from 8.7% to 15.8% (p = 0.018) between the two eras. Unadjusted survival analysis revealed improved overall survival (OS) between eras with 5-year OS 53.2% vs. 42.7% and 10-year OS 42.7% vs. 26.4% in the NAC vs. pre-NAC cohorts, respectively (p = 0.016). CONCLUSIONS: In this review of 20 years of experience, we report a dramatic rise in the use of NAC after adoption of a multidisciplinary pathway that is associated with expected survival benefits.

A Novel Liver-targeted Testosterone Therapy for Sarcopenia in Androgen Deprived Men With Prostate Cancer.

OBJECTIVE: Androgen deprivation therapy (ADT) reduces muscle and bone mass, increasing frailty in men with prostate cancer. The liver mediates the whole body anabolic effects of testosterone. Based on first-pass metabolism, liver-targeted testosterone treatment (LTTT) entails oral delivery of a small dose of testosterone that does not raise peripheral blood testosterone levels. LTTT reduces blood urea and stimulates protein anabolism in hypogonadal men and postmenopausal women. We investigated whether LTTT prevents loss of lean and bone mass during ADT. METHOD: A 6-month, double-blind, placebo-controlled study of testosterone 40 mg/day in 50 men. Primary outcome measures were lean mass and bone mineral content (BMC). Testosterone, urea and prostate-specific antigen (PSA) were monitored. Patients were withdrawn if PSA exceeded 4 ng/mL. RESULTS: 42 patients completed the study. Mean (95% CI) testosterone rose during LTTT but not placebo treatment [∆ 2.2 (1.3-3.0) vs -0.7 (-1.5 to 0.2) nmol/L; P < 0.01]. Mean PSA level did not change significantly during either treatment. Blood urea fell [∆ -0.4 (-0.9 to -0.1) mmol/L] during LTTT but not placebo [∆ 0.05 (-0.8 to 0.9) mmol/L]. BMC [∆ 49 (5 to 93) g; P < 0.02] and lean mass [∆ 0.8 (-0.1 to 1.7) kg; P = 0.04) increased compared to placebo. Five patients on LTTT withdrew from increased PSA levels, all returning to baseline levels. CONCLUSION: LTTT shows promise as a simple therapy for preventing sarcopenia and bone loss during ADT. LTTT may induce reversible PSA rise in some patients. Further studies are required to optimize LTTT dose in ADT. LTTT has potential application in other catabolic states in men and women.

Outcome prediction following radical nephroureterectomy for upper tract urothelial carcinoma.

OBJECTIVE: To predict overall survival, cancer, and metastasis specific survival in upper tract urothelial carcinoma (UTUC) following radical nephroureterectomy (RNU). MATERIALS AND METHODS: All nonmetastatic UTUC patients who underwent RNU with a curative intent at 1 institution between December 1998 and January 2017 were included.  Detailed data were collected. End points for this study included OS, CCS, and MFS. Univariate and multivariate analysis were conducted. Log Rank tests and Kaplan-Meier curves were generated. Backward elimination and boot strapping was used to identify the most parsimonious model with the smallest number of variables in order to predict the outcomes of interest. A separate second institution data base was used for external validation. RESULTS: There were 218 patients in the development cohort. Mean follow-up was 42 months (±39.6). There was 99 (45.4%) deaths, 28 (12.8%) cancer related deaths, 72 (33%) recurrences, and 54 (24.8%) metastases. The c-index for our model was 0.71 for OS, 0.72 for MFS and 0.74 for CSS. The nomograms did not show significant deviation from actual observations using our calibration plots. We divided the patient into 3 different groups (low, intermediate and high risk) based on their final total score for each outcome and compared them. On external validation our accuracy was 78.4%, 71.4%, and 75.3% for OS, CSS, and MFS survival respectively. CONCLUSION: We designed a predictive model for survival outcomes following RNU in UTUC. This model uses simple, readily available data for patients without the need for expensive or additional testing.

Prostate cancer and the role of biomarkers.

PURPOSE: To review available prostate cancer biomarkers and their performance in a clinical order, from prostate cancer detection, to treatment of localized and advanced disease. METHODS: We used an electronic literature search of the PubMed database using the key words "prostate biomarkers," "genomic markers," and "prostate cancer screening," as well as specific biomarkers, until March 2019. RESULTS: Prostate-specific antigen (PSA) lacks sensitivity for prostate cancer detection, and PSA derivatives have slightly improved its specificity, but have not resolved the limitations of PSA screening. Prostate cancer biomarkers have emerged as an ancillary tool to guide the clinical decision-making in different clinical scenarios. Urine-based tests can identify patients who may benefit from a prostate biopsy, and issue-based markers are helpful in guiding the decision regarding a second biopsy, stratifying patient with newly diagnosed prostate cancer to active surveillance or treatment, and identifying patients who may benefit from adjuvant treatment after surgery. CONCLUSIONS: New biomarkers have improved risk stratification in diagnosing and treating prostate cancer. Many of these markers are still considered experimental, and their efficacy and cost utility have not been determined.

Incidence, Outcomes, and Prediction of Postoperative Urinary Retention After a Nonurologic Procedure.

PURPOSE: To develop a prognostic model to estimate postoperative urinary retention (POUR) after lower limb arthroplasty. METHODS: One thousand two hundred twenty patients underwent 1,374 joint replacement operations (812 knees and 562 hips) between December 2008 and May 2014. Detailed variables were collected. A multivariable logistic regression model was used to identify the independent predictors for POUR. Boot strapping and stepwise elimination was used to design a predictive nomogram. RESULTS: There were 124 incidents of POUR (9.02%) in 118 patients (90 knee, 34 hip, P = 0.001). On univariate analysis, patients who developed POUR were older (P < 0.001), had higher American Association of Anesthesiology scores (P = 0.007), underwent knee replacement (0.001), were obese (body mass index > 35) (P = 0.04), and were hypertensive (P = 0.029), with a history of benign prostatic hyperplasis (BPH) (P < 0.001) or neurologic disorders (P = 0.024). On multivariable analysis, age (60 to 69 years, P = 0.023, 70 to 79 yrs P = 0.008, >80 years P = 0.003), knee replacement (P = 0.014), and history of BPH (P = 0.013) were the independent predictors of POUR. A score was assigned to each predictor (total = 31). The C-index was 0.65. There were three risk categories as follows: 0 to 50, 51 to 85, and 86+ points resulting in 3.3%, 7.2%, and 14.0% risk of retention, respectively. DISCUSSION: This nomogram reliably predicts the risk of POUR in patients undergoing hip and knee arthroplasties and may help planning preoperative interventions to decrease the risk of this complication.

Assessment of Polyethylene Glycol Hydrogel Spacer and Its Effect on Rectal Radiation Dose in Prostate Cancer Patients Receiving Proton Beam Radiation Therapy.

PURPOSE: To assess the efficacy of placing a polyethylene glycol (PEG) spacing hydrogel in patients undergoing proton beam radiation therapy for prostate cancer. This study also aims to assess the effect on rectal radiation dose of prostate-rectum separation in various anatomic planes. METHODS AND MATERIALS: Seventy-two consecutive prostate cancer patients undergoing conventionally fractionated pencil beam scanning proton radiation therapy with and without hydrogel placement were compared. Magnetic resonance images taken after hydrogel placement measured prostate-rectum separation and were correlated to rectal dosing and rectal toxicity. Univariate analysis of clinical variables and radiation dosing was conducted using nonparametric Wilcoxon rank-sum test with continuity correction between groups (hydrogel spacer vs controls). Spearman's rank correlation coefficient assessed relationships between the various anatomic dimensions of perirectal space and rectal radiation dosing. RESULTS: Fifty-one patients had hydrogel placement before therapy and 21 did not. There was a 42.2% reduction in rectal dosing (mL3 rectum) in hydrogel patients (P < .001). Increasing midline sagittal lift resulted in a greater mitigation of total rectal dose (P = .031). The degree of prostate surface area coverage on coronal plane did not correlate with further reductions in rectal radiation dose (P = .673). Patients who had PEG hydrogels placed reported more rectal side effects during treatment compared with those patients who did not (35.3% vs 9.5%, P = .061). At median 9.5-month follow-up, there was no difference in reporting of grade ≤2 rectal toxicity between the 2 groups (7.7% vs 7.1%, P = .145). CONCLUSIONS: Polyethylene glycol hydrogel placement before pencil proton beam radiation therapy for prostate cancer reduced rectal radiation dose. The most important factor reducing total rectal dose was the degree of sagittal midline separation created by the PEG hydrogel. This is the largest study with the longest follow-up to investigate hydrogel placement in the proton beam radiation setting.

Robot Assisted Renal Allograft Nephrectomy: Initial Case Series and Description of Technique.

OBJECTIVE: To evaluate the outcomes and perioperative complication rates following robot- assisted transplant nephrectomy ((RATN). METHODS: All patients who underwent RATN at our institution were included. No exclusion criteria were applied. Clinical records were retrospectively reviewed and reported. This included preoperative, intraoperative, and postoperative outcomes. Complications were reported utilizing the Clavien-Dindo classification system. Descriptive statistics were reported using frequencies and percentages for categorical variables, means and standard deviation for continuous variables. RESULTS: Between July 2014 and April 2018, 15 patients underwent RATN. Most patients had the transplant in the right iliac fossa (13/15). Ten patients underwent a concomitant procedure. The total operative time for the entire cohort was 336 (±102) minutes (including cases who had concomitant procedures) and 259 (±46 minutes) when cases with concomitant procedures were excluded. Mean estimated blood loss was 383 (±444) mL. Postoperatively, 3 patients required blood transfusion. Average hospital stay was 4 (±2.7) days. Most patients had finding consistent with graft rejection on final pathology. There were 5 complications; 3 of which were minor (grade 2 = 2 and grade 3 = 1); one patient had a wound infection requiring dressing (3A) and one patient died due to pulmonary embolism following discharge. Limitations include small series and retrospective nature of the study. CONCLUSION: This case series demonstrate that RATN is technically feasible. With continued experience and larger case series, the robotic approach may provide a minimally invasive alternative to open allograft nephrectomy.

Comparison of Open and Robot Assisted Radical Nephrectomy With Level I and II Inferior Vena Cava Tumor Thrombus: The Mayo Clinic Experience.

OBJECTIVE: To compare the perioperative and oncologic outcomes associated with open radical nephrectomy with tumor thrombus (O-RNTT) vs robot assisted radical nephrectomy with tumor thrombus (RA-RNTT). Renal cell carcinoma with venous tumor thrombus has traditionally been managed through an open surgical approach. The robot assisted approach may offers improved perioperative outcomes compared to open, but there are few studies comparing these 2. METHODS: We analyzed patients with renal cell carcinoma and inferior vena cava tumor thrombus between 1998 and 2018, comparing perioperative and oncologic outcomes of these patients with Level I and Level II thrombus. Cohorts were stratified by surgical approach: O-RNTT vs RA-RNTT. Univariate analysis was conducted using chi-squared test and t tests when appropriate. Kaplan-Meier estimates were used to evaluate survival. RESULTS AND LIMITATION: Twenty-seven patients were in the O-RNTT group, and 24 in the RA-RNTT group. Patients in the RA-RNTT group, compared to the O-RNTT group, demonstrated shorter length of stay (3 vs 7 nights, P = .03), lower estimate blood loss (450 vs 1800 mL, P <.01), and lower transfusion rate (21% vs 82%, P <.01). The RA-RNTT group had 26% fever complications compared to the open (17% vs 43%, P <.01). There was no significant difference in estimated overall survival or recurrence-free survival between the O-RNTT and RA-RNTT groups. CONCLUSION: RA-RNTT produced a shorter length of stay, less transfusions, and a lower rate of complications with no significant difference in overall survival.

Predictive Factors for Achieving the Recommended AUA Daily Urine Production in Patients With Nephrolithiasis.

OBJECTIVE: To identify factors that predict kidney stone patient's ability to produce 2.5 L urine volume per day on metabolic evaluation. PATIENTS AND METHODS: In a retrospective chart review, the first analysis evaluated initial 24-hour urine collections with respect to those who achieved or did not achieve a urine volume of 2.5 L/day. The second analysis evaluated those who achieved or did not achieve a daily urine volume of 2.5 L on their subsequent collection. Several variables were assessed. RESULTS: Patients' initial collections (n=1100) that achieved 2.5 L/day (n=274) were of younger age and had a higher body mass index, increased urine sodium, phosphorus, calcium levels, increased protein catabolic rate, and decreased supersaturation of calcium oxalate. In the second analysis (n=273), decreased supersaturation of calcium oxalate, increased urine urea nitrogen level, and increased protein catabolic rate were observed in subsequent collections with a urine volume of 2.5 L/day or more. Patients with a diagnosis of hyponatremia were less likely to achieve 2.5 L/day urine volume. Collection date, other comorbidities, and diuretic use were not associated with achieving 2.5 L/day urine volume. Patients' mean creatinine per kilogram for all study cohorts were within the range of adequate collection. CONCLUSION: Predictive factors for a urine volume of 2.5 L/day or more include increased fluid intake, higher salt and animal protein diet, elevated body mass index, and male sex. Patients with these factors may require interventions other than hydration recommendations to optimize their prevention of future kidney.