Cone beam computed tomography for detecting residual stones in percutaneous nephrolithotomy, a randomized controlled trial (CAPTURE) protocol.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is the standard surgical treatment method for large kidney stones. Its aim is to achieve a stone-free status, since any residual fragments (RFs) after PCNL are likely to cause additional morbidity or stone growth. Enhancing intraoperative detectability of RFs could lead to increased stone-free rates and decreased re-intervention rates. Cone beam computed tomography (CBCT) has recently been introduced in urology as a feasible method for intraoperatively imaging RFs. The aim of this trial is to determine the added value of CBCT in percutaneous nephrolithotomy, by measuring differences in stone-related morbidity for patients with procedures in which a CBCT is used versus patients with procedures without the use of CBCT. METHODS: The CAPTURE trial is an investigator-initiated single-center, randomized controlled trial (RCT) in adult patients who have an indication for percutaneous nephrolithotomy. A contemporary percutaneous nephrolithotomy is performed. Once the surgeon is convinced of a stone-free status by means of fluoroscopy and nephroscopy, randomization allocates patients to either the study group in whom an intraoperative CBCT scan is performed or to the control group in whom no intraoperative CBCT scan is performed. The main endpoint is the stone-free status as assessed four weeks postoperatively by low-dose non-contrast abdominal CT, as a standard follow-up procedure. Secondary endpoints include the number of PCNL procedures required and the number of stone-related events (SREs) registered. The total study population will consist of 320 patients that undergo PCNL and are eligible for randomization for an intraoperative CBCT scan. DISCUSSION: We deem a randomized controlled trial to be the most effective and reliable method to assess the efficacy of CBCT in PCNL. Though some bias may occur due to the impossibility of blinding the urologist at randomization, we estimate that the pragmatic nature of the study, standardized circumstances, and follow-up methods with pre-defined outcome measures will result in a high level of evidence. TRIAL REGISTRATION: Netherlands Trial Register (NTR) NL8168 , ABR NL70728.042.19. Registered on 15 October 2019. Prospectively registered.

Intraoperative cone beam computed tomography for detecting residual stones in percutaneous nephrolithotomy: a feasibility study.

Cone beam computed tomography (CBCT) provides multiplanar cross-sectional imaging and three-dimensional reconstructions and can be used intraoperatively in a hybrid operating room. In this study, we investigated the feasibility of using a CBCT-scanner for detecting residual stones during percutaneous nephrolithotomy (PCNL). Intraoperative CBCT-scans were made during PCNL procedures from November 2018 until March 2019 in a university hospital. At the point where the urologist would have otherwise ended the procedure, a CBCT-scan was made to image any residual fragments that could not be detected by either nephroscopy or conventional C-arm fluoroscopy. Residual fragments that were visualized on the CBCT-scan were attempted to be extracted additionally. To evaluate the effect of this additional extraction, each CBCT-scan was compared with a regular follow-up CT-scan that was made 4 weeks postoperatively. A total of 19 procedures were analyzed in this study. The mean duration of performing the CBCT-scan, including preparation and interpretation, was 8 min. Additional stone extraction, if applicable, had a mean duration of 11 min. The mean effective dose per CBCT-scan was 7.25 mSv. Additional extraction of residual fragments as imaged on the CBCT-scan occurred in nine procedures (47%). Of the follow-up CT-scans, 63% showed a stone-free status as compared to 47% of the intraoperative CBCT-scans. We conclude that the use of CBCT for the detection of residual stones in PCNL is meaningful, safe, and feasible.

[Asymptomatic microscopic haematuria: usually not a problem]. / Asymptomatische microscopische hematurie.

Asymptomatic microscopic haematuria is a common finding and can have many different causes. Only a small fraction of patients referred for microscopic haematuria have an underlying urological malignancy or serious nephrogenic disease. It is important that only those patients with microscopically confirmed microscopic haematuria are referred. Often no cause can be found even after thorough diagnostic work-up. The work-up of microscopic haematuria can include urethrocystoscopy, ultrasound, multi-phase CT and cytology. These procedures are not only costly, but can have associated health risks and may also cause patients anxiety and distress. There is no evidence to support the hypothesis that microscopic haematuria is the precursor of macroscopic haematuria, which is significantly more likely to have serious underlying causes. A diagnostic work-up should be initiated with caution.

The interobserver variability of digital rectal examination in a large randomized trial for the screening of prostate cancer.

BACKGROUND: To analyze to what extent the percentage of suspicious digital rectal examination (DRE) findings vary between examiners and to what extent the percentage of prostate cancers (PCs) detected in men with these suspicious findings varies between examiners. METHODS: In the first screening round of the European Randomized study of Screening for PC (ERSPC) Rotterdam, 7,280 men underwent a PSA-determination and DRE of whom 2,102 underwent prostate biopsy (biopsy indication PSA > or = 4.0 ng/ml and/or suspicious DRE and/or TRUS). Descriptive statistics of DRE-outcome per PSA-range were used to determine the observer variability of six examiners. Because this analysis did not correct properly for other predictors of a suspicious DRE (PSA-level, biopsy indication, TRUS-outcome, prostate volume and age), a logistic regression analysis controlling for these explanatory variables was performed as well. RESULTS: In 2,102 men biopsied, 443 PCs were detected (PPV = 21%). For all PSA levels the percentage suspicious DRE varied between examiners from 4% to 28% and percentage PC detected in men with a suspicious DRE varied from 18% to 36%. Logistic regression analysis showed that three of six examiners considered DRE significantly more often abnormal than others (ORs 3.48, 2.80, 2.47, P < 0.001). For all examiners the odds to have PC was statistically significantly higher in case of a suspicious DRE (ORs 2.21-5.96, P < 0.05). This increased chance to find PC was not significantly observer-dependent. CONCLUSIONS: Three of six examiners considered DRE significantly more often suspicious than the others. However, under equal circumstances a suspicious DRE executed by each examiner increased the chance of the presence of PC similarly.

Overdiagnosis and overtreatment of early detected prostate cancer.

Early detection of prostate cancer is associated with the diagnosis of a considerable proportion of cancers that are indolent, and that will hardly ever become symptomatic during lifetime. Such overdiagnosis should be avoided in all forms of screening because of potential adverse psychological and somatic side effects. The main threat of overdiagnosis is overtreatment of indolent disease. Men with prostate cancer that is likely to be indolent may be offered active surveillance. Evaluation of active surveillance studies and validation of new biological parameters for risk assessment are expected.

Very late local recurrence after surgery for prostate cancer unaccompanied by detectable PSA levels.

The possibility and possible aetiology of local prostate cancer (PC) recurrence despite undetectable prostate-specific antigen (PSA) levels are highlighted. A case of a local recurrence 8.5 years after radical prostatectomy for Gleason 3+4 PC is presented. It demonstrates that PC can recur, even after a prolonged period of time (8.5 years), despite undetectable levels (i.e. <0.02 ng/ml) of PSA. In conclusion, the decision to omit digital rectal examination from the follow-up regimens of men with undetectable PSA levels could be justified. In such exceptional cases, however, PC recurrence would be either missed or would only be diagnosed after a considerable delay.