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Failure to suppress testosterone below 0.7 nM in castrated prostate cancer patients is associated with poor clinical outcomes. Testosterone levels in castrated patients are therefore routinely measured. Although mass spectrometry is the gold standard used to measure testosterone, most hospitals use an immunoassay method. In this study, we sought to evaluate the accuracy of an immunoassay method to measure castrate testosterone levels, with mass spectrometry as the reference standard. We retrospectively evaluated a cohort of 435 serum samples retrieved from castrated prostate cancer patients from April to September 2017. No follow-up of clinical outcomes was performed. Serum testosterone levels were measured in the same sample using liquid chromatography coupled with tandem mass spectrometry and electrochemiluminescent immunoassay methods. The mean testosterone levels were significantly higher with immunoassay than with mass spectrometry (0.672 ± 0.359 vs 0.461 ± 0.541 nM; P < 0.0001). Half of the samples with testosterone ≥0.7 nM assessed by immunoassay were measured <0.7 nM using mass spectrometry. However, we observed that only 2.95% of the samples with testosterone <0.7 nM measured by immunoassay were quantified ≥0.7 nM using mass spectrometry. The percentage of serum samples experiencing testosterone breakthrough at >0.7 nM was significantly higher with immunoassay (22.1%) than with mass spectrometry (13.1%; P < 0.0001). Quantitative measurement of serum testosterone levels >0.7 nM by immunoassay can result in an inaccurately identified castration status. Suboptimal testosterone levels in castrated patients should be confirmed by either mass spectrometry or an immunoassay method validated at low testosterone levels and interpreted with caution before any changes are made to treatment management.

Purpose of the review: Vesicoureteral reflux (VUR) is a common pathology encountered in pediatric urology. If left untreated, this condition can lead to infectious complications, hypertension and loss of renal function by scars. There is a trend for minimally invasive procedures to minimise treatment-related complications. Endoscopic subureteral injection of bulking agent in the treatment of VUR is an example of minimally invasive options. Several bulking agents have been studied and the perfect agent has not yet been discovered. Polyacrylamide hydrogel is a relatively new agent used to treat VUR and its use will be reviewed. Recent findings: Three modern studies from a Canadian group have evaluated the use of polyacrylamide hydrogel for endoscopic injection to treat VUR. The first study reported a cure rate of 81.2% without major complication. In the second study, injection of polyacrylamide hydrogel was compared to dextranomer hyaluronic acid and no significant difference was observed, with overall success rate of 73.1% and 77.5% respectively. The third trial evaluated the long-term efficacy and safety of polyacrylamide hydrogel with a 36-month follow-up. Overall success at 3 months was 70.7% and no patient had de novo hydronephrosis or calcification of the agent at 36 months. Conclusion: Polyacrylamide hydrogel seems to be a safe and effective alternative bulking agent in the treatment of VUR. The contribution from other centers to validate those data would be valuable.

Background: Androgen deprivation therapy (ADT) is the standard of care for prostate cancer treatment. Studies suggest that patients with testosterone levels below 0.7 nM have a longer time to castration resistance. Using the most accurate testosterone measurement method, namely mass spectrometry (MS), we sought to determine if a lower testosterone level under ADT could be associated with longer time to castration resistance.Methods: This retrospective study included 138 prostate cancer patients undergoing noncurative continuous ADT for which we had access to testosterone measurements assessed by MS. For 108 samples, paired immunoassays (IA) testosterone measurement was available. Primary outcome was time to castration-resistant prostate cancer (CRPC). The Contal and O'Quigley method was used to determine the optimal testosterone castration cut-off point considering the outcome and timeto-event variables. Relationship between testosterone levels assessed either by IA or MS and time to CRPC was evaluated using Cox regression.Results: Mean testosterone level was 0.370 nM by IA and 0.275 nM as assessed by MS. The optimal testosterone cut-off point identified to predict time to CRPC was of 0.705 nM for IA and of 0.270 nM for MS. While no significant difference for time to CRPC was found between patients showing IA testosterone level ≥0.705 nM versus <0.705 nM (hazard ratio [HR]: 1.579; 95% confidence interval [CI]: 0.908-2.745), patients with MS testosterone ≥0.270 nM had an increased risk of progression to CRPC compared to MS testosterone <0.270 nM in univariate (HR: 1.717; 95% CI: 1.160-2.541) and multivariate analysis (HR: 1.662; 95% CI: 1.043-2.648). Conclusions:The higher sensitivity of MS testosterone measurement methods allows the identification of a lower castration threshold and leads to early identification of patients more likely to progress to CRPC. These patients would

ObjectiveTo assess if estimated glomerular filtration rate (eGFR) can replace measured GFR (mGFR) in partial nephrectomy (PN) trials, using data from a randomised clinical trial.Patients and methodsWe conducted a post hoc analysis of the renal hypothermia trial. Patients underwent mGFR with diethylenetriaminepentaacetic acid (DTPA) plasma clearance preoperatively and 1 year after PN. The eGFR was calculated using the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD‐EPI) creatinine equations incorporating age and sex, with and without race: 2009 eGFRcr(ASR) and 2009 eGFRcr(AS), and the 2021 equation that only incorporates age and sex: 2021 eGFRcr(AS). Performance was evaluated by determining the median bias, precision (interquartile range [IQR] of median bias), and accuracy (percentage of eGFR within 30% of mGFR).ResultsOverall, 183 patients were included. Pre‐ and postoperative median bias and precision were similar between the 2009 eGFRcr(ASR) (−0.2 mL/min/1.73 m2, 95% confidence interval [CI] −2.2 to 1.7, IQR 18.8; and −2.9, 95% CI −5.1 to −1.5, IQR 15, respectively) and 2009 eGFRcr(AS) (−0.3 mL/min/1.73 m2, 95% CI −2.4 to 1.5, IQR 18.8; and −3.0, 95% CI −5.7 to −1.7, IQR 15.0, respectively). Bias and precision were worse for the 2021 eGFRcr(AS) (−8.8 mL/min/1.73 m2, 95% CI −10.9 to −6.3, IQR 24.7; and −12.0, 95% CI −15.8 to −8.9, IQR 23.5, respectively). Similarly, pre‐ and postoperative accuracy was >90% for the 2009 eGFRcr(ASR) and 2009 eGFRcr(AS) equations. Accuracy was 78.6% preoperatively and 66.5% postoperatively for 2021 eGFRcr(AS).ConclusionThe 2009 eGFRcr(AS) can accurately estimate GFR in PN trials and could be used instead of mGFR to reduce cost and patient burden.

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