Risk of Radiation from Computerized Tomography Urography in the Evaluation of Asymptomatic Microscopic Hematuria

Is the excretory phase necessary to identify upper tract urothelial neoplasms at CT urography? A 10-year population-based study

PURPOSE

To assess the proportion of upper tract urothelial carcinomas (UTUC) that are evident without the excretory phase at CT urography (CTU), and the proportion of potentially avoidable radiation.

METHODS

UTUCs diagnosed between January 2008-December 2017 were retrospectively identified from a population-based cancer registry. For each patient, US, non-urographic CT, and MRI exams were assessed for a primary mass and secondary imaging findings (hydronephrosis, urinary tract thickening, luminal distention, fat stranding, and lymphadenopathy/metastatic disease). CTUs were assessed for primary and secondary findings, and whether the tumor was evident as a filling defect on excretory phase. The dose-length product (DLP) of potentially avoidable excretory phases was calculated as a fraction of total DLP.

RESULTS

288 patients (mean age, 72±11 years, 165 males) and 545 imaging examinations were included. Of 192 patients imaged with 370 non-urographic CTs, a primary mass was evident in 154 (80.2%), secondary findings were evident in 172 (89.6%), and primary or secondary findings were evident in 179 (93.2%). Of 175 CTUs, primary and secondary findings were evident in 157 (89.7%) and 166 (94.9%) examinations, respectively, and primary or secondary findings were evident in 170/175 (97.1%). 131/175 (74.9%) UTUCs were evident as a filling defect, including the 5/175 (2.9%) UTUCs without primary or secondary findings. Of 144 CTUs with available DLP data, the proportion of potentially avoidable radiation was 103.7/235.8 (44.0%) Gy⋅cm.

CONCLUSION

In our population, almost all UTUCs were evident via primary or secondary imaging findings without requiring the excretory phase. These results support streamlining protocols and pathways.

The role of URO17® in diagnosis and follow up of bladder cancer patients

OBJECTIVE

to evaluate the role of urinary URO17® biomarker in the detection of urothelial tumors in haematuria patients and the detection of recurrence in non-muscle invasive bladder urothelial tumors.

MATERIALS AND METHODS

Our study was formed of two cohorts of patients, group I represents patients presenting with haematuria (n = 98), while group II represents patients with known non-muscle invasive bladder cancers on their scheduled follow up cystoscopic investigation (n = 51). For both groups, patients were asked to provide urine samples before cystoscopy, either primary as part of the haematuria investigation or as a scheduled follow-up. Urine samples were sent anonymously for standard urine cytology and URO17® biomarker immunostaining. Results were compared to cystoscopic findings using Chi-square analysis and Fisher's exact test (P < 0.05).

RESULTS

Group I was formed of 98 patients, with an average age of 60 years. URO17® showed 100% sensitivity and 96.15% specificity with a negative predictive value (NPV) of 100 and a positive predictive value (PPV) of 95.83. The results showed statistical significance with P value < 0.001. Group II was formed of 51 patients, with an average age of 75 years. URO17® was shown to have a sensitivity of 85.71% and NPV of 95.45. Eleven patients of group II were on scheduled BacillusCalmette-Guerin (BCG) and another 5 received Mitomycin C (MMC). The overall results of both groups combined (n = 149) showed statistical significance between flexible cystoscopy results and the results of urinary URO17® and urine cytology.

CONCLUSION

URO17® has a potential to be a reliable test for diagnosis and follow up of urothelial cancer patients and a screening tool adjunct to flexible cystoscopy.

TRIAL REGISTRATION

Not applicable as the current study is not a clinical trial, as per according to the National Institutes of Health, "studies that involve a comparison of methods and that do not evaluate the effect of the interventions on the participant do not meet the NIH clinical trial definition."

Discrepant guidelines in the evaluation of hematuria

PURPOSE

To assess discrepancies in current imaging recommendations for hematuria among North American societies: American College of Radiology (ACR), American Urological Association (AUA), and Canadian Urological Association (CUA).

METHODS

The latest available ACR Appropriateness Recommendations, AUA guidelines, and CUA guidelines were reviewed. AUA and CUA guidelines imaging recommendations by variants and level of appropriateness were converted to match the style of ACR. Imaging recommendations including modality, anatomy, and requirement for contrast were recorded.

RESULTS

Clinical variants included microhematuria without risk factors, microhematuria with risk factors, gross hematuria, and microhematuria during pregnancy. CUA recommends ultrasound kidneys as the first-line imaging study in the first 3 variants; pregnancy is not explicitly addressed. For hematuria without risk factors, ACR does not routinely recommend imaging, while AUA recommends shared decision-making to decide repeat urinalysis versus cystoscopy with ultrasound kidneys. For hematuria with risk factors and gross hematuria, ACR recommends CT urography; MR urography can also be considered in gross hematuria. AUA further stratifies intermediate- and high-risk patients, for which ultrasound kidneys and CT urography are recommended, respectively. For pregnancy, ACR and AUA both recommend ultrasound kidneys, though AUA additionally recommends consideration of CT or MR urography after delivery.

CONCLUSION

There is no universally agreed upon algorithm for diagnostic evaluation. Discrepancies centered on the role of upper tract imaging with ultrasound versus CT. Prospective studies and/or repeat simulation studies that apply newly updated guidelines are needed to further clarify the role of imaging, particularly for patients with microhematuria with no and intermediate risk factors.

Cornerstones of CT urography: a shared document by the Italian board of urogenital radiology

CT urography is a single term used to refer to different scanning protocols that can be applied for a number of clinical indications. If, on the one hand, this highlights the role of the radiologist in deciding the most suitable technique to perform according to the patient's needs, on the other hand, a certain confusion may arise due to the different technical and clinical variables that have to be taken into account. This has been well demonstrated by a previous work based on an online questionnaire administered to a population of Italian radiologists that brought out similarities as well as differences across the national country. Defining precise guidelines for each clinical scenario, although desirable, is a difficult task to accomplish, if not even unfeasible. According to the prementioned survey, five relevant topics concerning CT urography have been identified: definition and clinical indications, opacification of the excretory system, techniques, post-processing reconstructions, and radiation dose and utility of dual-energy CT. The aim of this work is to deepen and share knowledge about these main points in order to assist the radiology in the daily practice. Moreover, a synopsis of recommendations agreed by the Italian board of genitourinary imaging is provided.

Persistent asymptomatic isolated microscopic hematuria in adolescents is not associated with an increased risk for early onset urinary tract cancer

OBJECTIVE

To elucidate the association between adolescent microscopic hematuria and early onset urothelial carcinoma and renal cell carcinoma.

METHODS

Nationwide, population-based, retrospective cohort study using medical data of 970,366 adolescents aged 16 through 19 years (58.6% male) examined for fitness for military service between 1980 and 1997. Diagnoses of persistent isolated microscopic hematuria were given after thorough work up process excluding any other renal abnormalities. Incident cases of urothelial carcinoma and renal cell carcinoma diagnosed during the years of 1982 to 2012 were retrieved from the Israeli National Cancer Registry. Cox proportional hazards models were used to estimate the hazard ratio (HR) separately for urothelial carcinoma and renal cell carcinoma.

RESULTS

During a cumulative follow-up of 22,115,629 person-years (median follow-up, 22.8), persistent isolated microscopic hematuria was diagnosed among 5509 (0.6%) adolescents. Urothelial carcinoma and renal cell carcinoma developed in 332 (3 among those with persistent isolated microscopic hematuria) and 292 (2) individuals, respectively. The adjusted HR for incident urothelial carcinoma among adolescents with isolated microscopic hematuria was 1.17 (95% CI, 0.38-3.66) and the adjusted HR for renal cell carcinoma was 1.02 (95% CI, 0.25-4.12).

CONCLUSIONS

Persistent asymptomatic isolated microscopic hematuria at adolescence was not associated with increased risk for urothelial carcinoma nor renal cell carcinoma.

Microhematuria in Women: Prevalence of Malignancy and Risk Score Evaluation

OBJECTIVES

To (1) determine the prevalence of urologic malignancy in women evaluated for microhematuria (MH) in a large university-based urology practice, (2) describe clinical features shared by women with MH, and (3) evaluate a risk score for urologic malignancy in women with MH.

METHODS

A retrospective chart review identified women with MH evaluated by a large, university-based urology practice between 2010 and 2020. Clinical and demographic variables associated with their evaluation, referral pattern, appropriateness of referral and evaluation, workup completed, and resulting diagnoses were reported. Patterns of repeat evaluations were also described. Patients were stratified as low-, intermediate-, or high-risk according to AUA/SUFU recommended risk stratification.

RESULTS

4456 charts resulted from an initial query based on females with ICD-9 and ICD-10 codes for MH between 2010-2020. 1730 patients (95.5% referrals v. 4.5% established urology patients) met criteria for inclusion in the study, and 1350 underwent evaluation for MH at the practice. Over 30% of referrals were considered inappropriate. 13 patients were diagnosed with urologic malignancy, all of whom were classified as intermediate- or high-risk according to AUA/SUFU criteria. Over 10% of patients had at least 2 evaluations for MH, with only 1 malignancy discovered on repeat evaluation for persistent MH.

CONCLUSIONS

Inappropriate referrals for MH are common. Incidence of urologic malignancy is incredibly low among women evaluated for MH, but especially among those classified as low- and intermediate-risk by new guidelines. Repeat evaluations for persistent, stable MH appear low yield in detecting malignancy.

Split vs. Single Bolus CT Urography: Comparison of Scan Time, Image Quality and Radiation Dose

The purpose of this study was to compare the scan time, image quality and radiation dose of CT urograms (CTU) using a split vs. single bolus contrast media injection technique. A total of 241 consecutive CTUs performed between August 2019-February 2020 were retrospectively reviewed. There were three study groups: Group 1, <50 years old, 50/80 cc split-bolus administered at 0 and 700 s post initiation of injection, with combined nephrographic and excretory phases; group 2, ≥50 years old, same split-bolus protocol; and group 3, ≥50 years old, 130 cc single bolus injection, with nephrographic and excretory phases acquired at 100 s and 460 s post injection initiation. The recorded data elements were scan time, number of excretory phases, imaging quality based on opacification of the urinary collecting system (<50%, 50–75%, 75–100%), and dose-length product (DLP). Associations between group and categorical variables were assessed (Chi-square); mean scan time and DLP were compared (one-way ANOVA). Following analysis, proportionally fewer CTUs required a repeat excretory phase in group 3 (32/112, 28.6%) than in groups 1 (25/48, 52.1%) and 2 (37/80, 46.3%) (p = 0.006). Mean scan time was significantly lower in group 3 (678 s) than in groups 1 (1046 s) and 2 (978 s) (p < 0.0001). There was no association between groups and image quality (p = 0.13). DLP was higher in group 3 (1422 ± 837 mGy·cm) than in groups 1 (1041 ± 531 mGy·cm) and 2 (1137 ± 646 mGy·cm) (p = 0.003). In conclusion, single bolus CTU resulted in significantly fewer repeat phases and faster scan time at the expense of a slightly higher radiation dose.

Assessment of Diagnostic Yield of Cystoscopy and Computed Tomographic Urography for Urinary Tract Cancers in Patients Evaluated for Microhematuria: A Systematic Review and Meta-analysis

IMPORTANCE

Microhematuria (MH) is a common finding that often leads to further evaluation for urinary tract cancers. There is ongoing debate about the extent to which patients with MH should be evaluated for cancer.

OBJECTIVE

To assess the diagnostic yield for detection of urinary tract cancers, specifically bladder cancer, upper tract urothelial carcinoma (UTUC), and kidney cell carcinoma, among patients evaluated for MH using cystoscopy and computed tomographic (CT) urography.

DATA SOURCES

MEDLINE, Scopus, and Embase were systematically searched for eligible studies published between January 1, 2009, and December 31, 2019.

STUDY SELECTION

Original prospective and retrospective studies reporting the prevalence of cancer among patients evaluated for MH were eligible. Two authors independently screened the titles and abstracts to select studies that met the eligibility criteria and reached consensus about which studies to include. Among 5802 records identified, 5802 articles were screened using titles and abstracts. After exclusions, 55 full-text articles were assessed for eligibility, with 39 studies selected for systematic review.

DATA EXTRACTION AND SYNTHESIS

This systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Studies were quantitatively synthesized using a random-intercept logistic regression model.

MAIN OUTCOMES AND MEASURES

The primary outcome was diagnostic yield, defined as the proportion of patients with a diagnosis of urinary tract cancer (bladder cancer, UTUC, or kidney cell carcinoma) after presentation with MH. Studies were stratified by the percentage of cystoscopy and CT urography use and by high-risk cohorts. The diagnostic yields of CT urography and cystoscopy were calculated for each cancer type.

RESULTS

A total of 30 studies comprising 24 366 patients evaluated for MH were included in the meta-analysis. The pooled diagnostic yield among all patients was 2.00% (95% CI, 1.30%-3.09%) for bladder cancer, 0.02% (95% CI, 0.0%-0.15%) for UTUC, and 0.18% (95% CI, 0.09%-0.36%) for kidney cell carcinoma. Stratification of studies that used cystoscopy and/or CT urography for 95% or more of the cohort produced diagnostic yields of 2.74% (95% CI, 1.81%-4.12%) for bladder cancer, 0.09% (95% CI, 0.01%-0.75%) for UTUC, and 0.10% (95% CI, 0.04%-0.23%) for kidney cell carcinoma. In high-risk cohorts, the diagnostic yields increased to 4.61% (95% CI, 2.34%-8.90%) for bladder cancer and 0.45% (95% CI, 0.22%-0.95%) for UTUC.

CONCLUSIONS AND RELEVANCE

This study's findings suggest that, given the low diagnostic yield of CT urography and the associated risks and costs, limiting its use to high-risk patients older than 50 years is warranted. Risk stratification, as recommended by the recent American Urology Association guidelines on MH, may be a better approach to tailor further evaluation.

Side-by-side evaluation of virtual non-contrast and post-contrast images improves detection of clinically significant urolithiasis on single-phase split bolus dual-energy CT urography

OBJECTIVES

Studies show insufficient sensitivity of virtual non-contrast (VNC) reconstructions for stone detection in dual-energy CT urography (DE-CTU). The aim of this study was to investigate if side-by-side-evaluation of both VNC and post-contrast images could increase the sensitivity of single-phase split bolus DE-CTU.

METHODS

Consecutive patients with haematuria who underwent split bolus DE-CTU on the same dual-source DE-CT scanner were retrospectively enrolled in the study. Intravenous furosemide and oral hydration were employed. Two readers, independently and then jointly in two separate sessions, recorded the location and the longest axial stone diameter on three randomised sets of images: separate VNC and post-contrast images, and side-by-side-reconstructions. True non-contrast (TNC) images served as the standard of reference.

RESULTS

A total of 83 urinary stones were detected on TNC images. Independent reader side-by-side-evaluation of VNC and post-contrast images yielded higher stone detection sensitivity (76 and 84%, respectively) compared to evaluation of only VNC (71 and 81%, respectively) or post-contrast images (64 and 80%, respectively). The sensitivity of joint reader evaluation of side-by-side-images reached almost 86% and was not significantly different from TNC images (p = 0.77). All stones larger than 3 mm were correctly detected by side-by-side-evaluation. Dose reduction of 55% could be achieved by omitting TNC scans.

CONCLUSION

Side-by-side-VNC and post-contrast image evaluation enable detection of clinically significant urolithiasis on single-phase split bolus DE-CTU with significant dose reduction.

ADVANCES IN KNOWLEDGE

This study shows that single-phase DE-CTU is feasible if VNC imaging is simultaneously utilised with post-contrast images.

Cancer Prevalence and Risk Stratification in Adults Presenting With Hematuria: A Population-Based Cohort Study

Objective

To calculate the prevalence of renal cell carcinoma (RCC), upper urinary tract urothelial carcinoma (UT-UC), and lower urinary tract urothelial carcinoma (LT-UC) in patients with gross asymptomatic microhematuria (AMH) and symptomatic microhematuria (SMH).

Patients and Methods

This study was a population-based retrospective descriptive study. The study was approved by both the Mayo Clinic Institutional Review Board and the Olmsted Medical Center Institutional Review Board, and the population used was Olmsted County residents. A total of 4453 patients who presented with an initial episode of hematuria from January 1, 2000, through December 30, 2010, were included. Of the 4453 patients (median age, 58 years; interquartile range, 44.6-73.3 years), 1487 (33.4%) had gross hematuria, 2305 (51.8%) had AMH, and 661 (14.8%) had SMH.

Results

In the 1487 patients with gross hematuria, the prevalence of RCC, UT-UC, and LT-UC was 1.3%, 0.8%, and 9.0%, respectively. In the 2305 patients with AMH, the prevalence of RCC, UT-UC, and LT-UC was 0.2%, 0.3%, and 1.6%, respectively. In the 661 patients with SMH, the prevalence of RCC, UT-UC, and LT-UC was 0.6%, 0.2%, and 0.3%, respectively. Age was the most relevant risk factor for any hematuria type.

Conclusion

This unique cohort study reported that the prevalence of RCC or UC in patients with AMH and SMH was low, especially in the young cohort, and a large number of intense work-ups, such as cystoscopy and computed tomography urography, currently conducted could be omitted if stratified by hematuria type and age.

Diagnostic yield of repeat evaluation for asymptomatic microscopic hematuria after negative initial workup

PURPOSE

The American Urological Association guideline for asymptomatic microhematuria recommends in patients with a negative initial workup, repeat workup should be considered for those with persistent/recurrent microhematuria. However, there is little data on the yield of repeat evaluation. Our hypothesis was that repeat workup yields a low detection rate of urologic malignancy.

MATERIALS AND METHODS

We retrospectively reviewed all patients at our institution who underwent microhematuria workup with cystoscopy and upper tract imaging from May 2010 to June 2016. Microhematuria was defined as ≥3 RBCs/HPF on a properly collected specimen in the absence of a benign cause. Demographics, age, smoking history, history of radiation, and findings on repeat cystoscopy and imaging were collected. Our primary endpoint was a new diagnosis of urologic malignancy.

RESULTS

Our initial cohort included 1,332 patients, of whom 21 were diagnosed with urothelial carcinoma and 7 with suspicious renal masses on initial workup. A total of 637 patients with negative initial workup had persistent/recurrent microhematuria. Repeat cystoscopy was performed in 161 (25%) patients at a median of 39 months, and repeat upper tract imaging was performed in 317 (50%) patients at a median of 39 months. Overall, repeat cystoscopy revealed new bladder cancer in 2 (1.2%) patients and repeat imaging revealed new suspicious renal mass in 4 (1.3%) patients.

CONCLUSIONS

We observed a low number of newly diagnosed malignancies among patients with persistent/recurrent asymptomatic microhematuria who had a prior negative workup. Additional research is required to determine the utility of a repeat AMH workup.

The role of URO17™ biomarker to enhance diagnosis of urothelial cancer in new hematuria patients—First European Data

Introduction and objectives

Novel biomarker research is vital for the progression of safe and thorough diagnostic medicine. There is now a need to improve the diagnosis of bladder cancer via a noninvasive urine test while balancing the risks of harm from investigational procedures, such as cystoscopy and radiological tests, against the likelihood of malignancy. We evaluate the diagnostic accuracy and sensitivity of Uro17™ urinary biomarker for the detection of urothelial cancer in hematuria patients in a prospective blinded validation study. Uro17™ is an immunobiomarker which binds to the oncoprotein Keratin 17, which is involved in the replication cycle of malignant cells. This study compared cystoscopic and histological investigations against Uro17™ results in patients being investigated for symptoms of urothelial cancer.

Materials and methods

After receiving both local and national ethics/protocol approval, 71 patients were consented and recruited into the study. All patients were scheduled to undergo cystoscopic investigation, and following recruitment, a urine sample was collected. Urine samples were anonymized and processed as per standard cytology protocols and stained using Uro17™ immunobiomarker. The pathologists assessing the results were blinded to the patient and background history, and the results were compared to the biopsy histology.

Results

The full cohort of enrolled patients consisted of 71 participants included. There were 55 males and 16 females, with an average age of 70. Thirteen were current smokers, 42 ex‐smokers, and 16 nonsmokers. The malignancies detected included both muscle‐invasive (n = 6) and non‐muscle‐invasive tumors (n = 38), and tumors of all grades and carcinoma in situ. Uro17™ was shown to have an overall sensitivity of 100% and a specificity of 92.6%, with a positive predictive value of 0.957 and negative predictive value of 1. Uro17™ investigation was positive in every case of urothelial malignancy.

Conclusions

Our current data indicates Uro17™ is a highly sensitive noninvasive bladder cancer urine detection test that can improve the diagnosis of Bladder cancer. This can further improve diagnostic capabilities in primary care, reduce the number of referrals to Urology department, and reduce the number of unnecessary invasive procedures for new patients with a suspected urinary bladder cancer.

Urological issues in pregnancy: A review for urologists

Urological issues in the pregnant patient present a unique clinical dilemma. These patients may be challenging to treat due to risks associated with medications and surgical procedures. This review aims to provide an update on the physiological changes and surgical risks in pregnancy. In addition, we review the approach for management of urolithiasis and urinary tract infections in pregnancy. Lastly, we highlight the importance of a multidisciplinary approach to placenta percreta, a condition not commonly addressed in urological education.

Accuracy of ultrasound vs computed tomography scan for upper urinary tract malignancies and development of a risk-based diagnostic algorithm for haematuria in a UK tertiary centre

PURPOSE

There is no consensus across guidelines on a diagnostic algorithm for upper urinary tract (UUT) evaluation following presentation with haematuria. Our aim is to compare the diagnostic accuracy of ultrasound (USS) compared to CT-scan for UUT malignancies and also determine the considerations important for a risk-based diagnostic protocol for haematuria.

METHODS

We reviewed our 'haematuria clinic' database to identify patients who had both USS and CT-scan for UUT evaluation between September 2015 and August 2017, and calculated the diagnostic accuracy of these imaging modalities for histologically confirmed UUT cancers. Furthermore, we identified risk factors in our diagnostic algorithm for haematuria and conducted regression analysis to determine their ability to predict UUT malignancies.

RESULTS

Overall, 575 patient records were studied. Age range was 21-92 years, M:F was 1.4:1, majority (81.2%) had visible haematuria, and 12 (2.1%) UUT cancers were diagnosed [renal cell carcinoma-1.4%; upper tract urothelial cancer-0.7%]. USS and CT-scan had diagnostic accuracy for UUT cancers of 95.8 and 99.1%, respectively (p < 0.001). Haematuria type was a significant consideration only on univariate analysis, while multivariate binary logistic regression showed that male gender, smoking, occupational exposure, and positive urologic history were the main risk factors associated with UUT malignancies.

CONCLUSION

USS and CT-scan have comparably high diagnostic accuracy for detecting UUT malignancies. USS may, therefore, be considered as the first-line UUT imaging modality when utilized in a risk-based diagnostic algorithm. Larger, multicentred studies are needed to validate our findings and influence guideline development.

Utilization and Yield of CT Urography: Are the American Urological Association Guidelines for Imaging of Patients With Asymptomatic Microscopic Hematuria Being Followed?

OBJECTIVE

The purposes of this study were to determine whether patients with asymptomatic microscopic hematuria undergoing CT urography (CTU) meet the American Urological Association criteria for radiologic evaluation and to determine the yield of CTU for upper tract malignancy.

MATERIALS AND METHODS

A retrospective review was conducted of consecutive CTU examinations performed for asymptomatic microscopic hematuria in adult patients. Patients with clinical evidence suggestive of a benign cause of hematuria (stone, urinary tract infection, trauma) or prior urologic malignancy were excluded. The study group included 419 patients (173 men, 246 women). CT reports were reviewed to identify causes of hematuria in all cases. Evaluate for appropriateness was conducted with 200 randomly allocated patients. Urinalysis results were reviewed, and appropriate use of CTU was defined as more than 3 RBCs per high-power field in the absence of urinary tract infection. Cystoscopy results after CTU were noted.

RESULTS

In total, 58 of 200 patients (29.0%; 95% CI, 23.2-35.6%) did not meet American Urological Association criteria for radiologic evaluation. Fifteen (7.5%) received dipstick analysis only. Thirty-eight (19.0%) had urinalysis results showing 0-2 RBCs per high-power field. Five patients (2.5%) were found to have urinary tract infections. No upper tract urothelial neoplasms were identified (0/419; 95% CI, 0.0-0.9%). One solid renal mass was identified without pathologic confirmation. One possible bladder mass was seen at CTU but not visualized at subsequent cystoscopy.

CONCLUSION

In 29.0% of examinations, CTU is performed for patients who do not meet the criteria for radiologic evaluation. The yield of CTU for upper urinary tract malignancy is low.

Diagnostic utility of axial imaging in the evaluation of hematuria: A systematic review and critical appraisal of the literature

INTRODUCTION

Increasing severity of hematuria is instinctively associated with higher likelihood of urological malignancy. However, the robustness of the evidentiary base for this assertion is unclear, particularly as it relates to the likelihood of upper urinary tract pathology. Thus, the value of axial imaging in the diagnostic workup of hematuria is unclear due to differences in the underlying patient populations, raising concern for sampling bias. We performed a systematic review to characterize the literature and association between severity of hematuria and likelihood of upper urinary tract cancer based on axial imaging.

METHODS

MEDLINE, EMBASE, and Cochrane were systematically searched for all studies reporting on adult patients presenting with hematuria. We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for reporting of this systematic review and meta-analysis and the Newcastle-Ottawa Scale for risk of bias assessment. Degree of hematuria was classified as "microscopic," "gross," or "unspecified." Three urological malignancies (bladder, upper tract urothelial, and renal cancer) were considered both individually and in aggregate. Random-effects model with pairwise comparisons was employed to arrive at the axial imaging diagnostic yields.

RESULTS

Twenty-nine studies were included, of which six (20.7%) reported on patients with gross hematuria only, four (13.8%) reported on patients with microscopic hematuria only, seven (24.1%) included both, and 12 (41.4%) did not define or specify the severity of hematuria. Of 29 studies, two (6.9%) were at high-risk of bias, 21 (72.4%) at intermediate-risk, and six (20.7%) at low-risk of bias using the Newcastle-Ottawa criteria. Based on axial imaging, rates of diagnoses of renal, upper tract urothelial, and bladder cancers differed with differing severity of hematuria. Notably, rates of renal and upper tract urothelial carcinoma were higher in studies of patients with unspecified hematuria severity (3.6% and 10.4%, respectively) than among patients with gross hematuria (1.5% and 1.3%, respectively). When all urological malignancies were pooled, patients with unspecified hematuria were diagnosed more frequently (19.5%) compared to those with gross (15.3%) and microscopic hematuria (4.5%, difference=1.51%, 99% confidence interval 3.6-26.5%).

CONCLUSIONS

Lack of granularity in the available literature, particularly with regards to patients with unspecified hematuria severity, limits the generalizability of these results and highlights the need for future studies that provide sufficient baseline information, allowing for firmer conclusions to be drawn.

Split bolus dual-energy CT urography after urine dilution: a one-stop shop for detection and characterisation of urolithiasis

AIM

To determine the diagnostic performance of split-bolus dual-energy computed tomography (CT) urography (SBDECTU) in the detection and characterisation of urolithiasis.

MATERIALS AND METHODS

This single-centre Institute Ethics Committee (IEC)-approved prospective study was conducted from April 2014 to November 2015. One hundred and thirty consenting adults with microscopic haematuria underwent dual-energy true non-enhanced CT (DETNE) of the whole abdomen followed by a SBDECTU. The SBDECTU protocol consisted of synchronous nephrogram-urogram acquisition following urine dilution by oral hydration and normal saline injection. Calculi were detected and characterised using virtual non-enhanced (VNE) images derived from SBDECT were compared with DETNE (the reference standard). The subjective image quality and radiation dose were compared.

RESULTS

Twenty-six participants had one or more calculi (total 129 calculi) detected on DETNE CT. The sensitivity and specificity of VNE on a per-patient basis were 100%. Of the 129 calculi, 118 were detected on VNE, with a sensitivity of 91.47% and an accuracy of 91.47%. Of the calculi, 83.9% (99/118) could be characterised on SBDECTU images. On VNE images, complete iodine subtraction was seen in 73.1% (19/26). By omitting DETNE CT, the mean dose-length product of 537.6±152.9 mGy and volume CT dose index of 10.9±2.9 mGy•cm² could have been saved.

CONCLUSION

SBDECTU has high diagnostic accuracy in the detection and characterisation of clinically significant urinary calculi at potentially half the radiation dose.

IDENTIFY: The investigation and detection of urological neoplasia in patients referred with suspected urinary tract cancer: A multicentre cohort study

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IDENTIFY study: The largest prospective cohort study of haematuria in secondary care.

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Contemporary urinary cancer detection rates and diagnostic strategies.

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The effectiveness of diagnostic tests, e.g. ultrasound, in detecting urinary cancer.

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Novel patient risk factors associated with bladder and upper tract urinary cancers.

Iodine Parameters in Triple-Bolus Dual-Energy CT Correlate With Perfusion CT Biomarkers of Angiogenesis in Renal Cell Carcinoma

OBJECTIVE. The purpose of this study is to determine the degree of the relationship between perfusion CT (PCT) parameters and iodine concentration metrics derived from triple-bolus dual-energy CT (DECT) and to compare the radiation dose delivered. SUBJECTS AND METHODS. This single-center prospective study was conducted from October 2015 to September 2017. Twenty-three consenting adults (15 men and eight women; mean [± SD] age, 56 ± 13 years [range, 25-78 years]) with renal cell carcinomas underwent consecutive PCT and triple-bolus DECT examinations. Triple-bolus DECT consisted of synchronous corticomedullary, nephrographic, and delayed phase scans acquired using a dual-source DECT scanner. Two readers independently analyzed blood flow, blood volume, and permeability, as measured by PCT, and iodine density and iodine ratio, as measured by triple-bolus DECT. Size-specific dose estimates were calculated for both groups. RESULTS. Interreader agreement was good for permeability (intraclass correlation coefficient [ICC] =.812) and blood flow (ICC = 0.849) and excellent for blood volume (ICC = 0.956), iodine density (ICC = 0.961), and iodine ratio (ICC = 0.956). Very strong positive correlations were found between blood volume and iodine density (p < 0.001) and between blood volume and iodine ratio (p < 0.001). Strong positive correlations were found between blood flow and iodine density (p < 0.001) and between blood flow and iodine ratio (p < 0.001). The correlations between permeability and iodine density (p = 0.01) and between permeability and iodine ratio (p = 0.02) were moderate. The mean size-specific dose estimate of triple-bolus DECT was approximately 15 times lower than that of PCT (p < 0.001). CONCLUSION. Quantitative iodine metrics derived from triple-bolus DECT showed significant correlation with CT parameters in renal cell carcinoma, with a significantly lower radiation dose.

Making sense of the CT Urogram

KEY POINTS

• There is great variation in the CT urogram protocol throughout the literature. • The study by Renard-Penna et al provides a useful rigorous expert consensus on CT urography technique. • The study by Rud et al suggests that the excretory phase may not be as necessary as previously thought for visualizing upper tract urothelial carcinoma.

Imaging protocols for CT urography: results of a consensus conference from the French Society of Genitourinary Imaging

OBJECTIVES

To develop technical guidelines for computed tomography urography.

METHODS

The French Society of Genitourinary Imaging organised a Delphi consensus conference with a two-round Delphi survey followed by a face-to-face meeting. Consensus was strictly defined using a priori criteria.

RESULTS

Forty-two expert uro-radiologists completed both survey rounds with no attrition between the rounds. Ninety-six (70%) of the initial 138 statements of the questionnaire achieved final consensus. An intravenous injection of 20 mg of furosemide before iodinated contrast medium injection was judged mandatory. Improving the quality of excretory phase imaging through oral or intravenous hydration of the patient or through the use of an abdominal compression device was not deemed necessary. The patient should be imaged in the supine position and placed in the prone position only at the radiologist's request. The choice between single-bolus and split-bolus protocols depends on the context, but split-bolus protocols should be favoured whenever possible to decrease patient irradiation. Repeated single-slice test acquisitions should not be performed to decide of the timing of excretory phase imaging; instead, excretory phase imaging should be performed 7 min after the injection of the contrast medium. The optimal combination of unenhanced, corticomedullary phase and nephrographic phase imaging depends on the context; suggestions of protocols are provided for eight different clinical situations.

CONCLUSION

This expert-based consensus conference provides recommendations to standardise the imaging protocol for computed tomography urography.

KEY POINTS

• To improve excretory phase imaging, an intravenous injection of furosemide should be performed before the injection of iodinated contrast medium. • Systematic oral or intravenous hydration is not necessary to improve excretory phase imaging. • The choice between single-bolus and split-bolus protocols depends on the context, but split-bolus protocols should be favoured whenever possible to decrease patient irradiation.

Examining the upper urinary tract in patients with hematuria-time to revise the CT urography protocol?

BACKGROUND

Three-phase CT urography (CTU) is the gold standard for evaluating the upper urinary tract in patients with hematuria. We aimed to evaluate the accuracy of CTU for detecting upper urothelial cell carcinomas (UCC) in patients with hematuria and negative cystoscopy. Secondly, we aimed to determine the tumor visibility on each CTU phase.

MATERIAL AND METHODS

This retrospective study included all patients with hematuria referred to CTU after a negative cystoscopy during 2016 and 2017. The original CTU reports were dichotomized as negative or positive. All patient charts were reviewed after a minimum of 18-month follow-up in order to register missed cancers. The results of biopsies and clinical follow-up were used as the reference standard. Two reviewers retrospectively evaluated the tumor visibility of each CT sequence in all true-positive CTUs.

RESULTS

We included 376 patients with hematuria who underwent CTU after a negative cystoscopy. Macroscopic and microscopic hematuria occurred in 87% (327) and 13% (49), respectively. The incidence of upper urothelial cell carcinoma was 1.9% (7), and the sensitivity of CTU was 100% (95% CI, 59-100), specificity was 99% (95% CI, 98-100), positive predictive value was 88% (95% CI, 47-99), and negative predictive value was 100% (95% CI, 99-100). The accuracy was 99% (95% CI, 90-100). All UCCs were visible on the nephrographic phase for both reviewers.

CONCLUSION

CTU is highly accurate for detecting upper UCCs. All cases were seen on the nephrographic phase. This suggests that the CTU protocol can be simplified.

KEY POINTS

• CT urography is highly accurate for detecting upper urothelial cell carcinomas. • All cancers were seen on the nephrographic phase. • All cancers were detected in patients with macroscopic hematuria.

Asymptomatic microscopic hematuria in women

PURPOSE OF REVIEW

The purpose of this review is to summarize the problem of asymptomatic microscopic hematuria (AMH) in women and the most recent publications on the topic.

RECENT FINDINGS

Urologic malignancy is rarely associated with AMH in low-risk women. Screening for urologic malignancy includes upper urinary tract imaging and cystoscopy. Renal ultrasound is a cost-effective first-line imaging modality in patients with AMH. Multiphasic computed tomography (CT) urography increases healthcare costs, the risk of secondary malignancy due to cumulative radiation exposure, and the discovery of incidental benign findings resulting in additional work-up. Cystoscopy is universally recommended as a diagnostic test in the evaluation of AMH but it is not without harm. Reliable risk factors for urologic malignancy in women are age, smoking, and possibly the presence of visible blood in the urine. Given the infrequency of these cancers and the performance characteristics of diagnostic testing in this context there is a need for better diagnostic strategies incorporating these risk factors in estimating the woman's risk.

SUMMARY

There is a need for sex-specific guidelines to risk stratify diagnostic evaluation for urologic malignancy in women with AMH. The low prevalence of these malignancies in women render diagnostic testing (e.g., cystoscopy and multiphasic CT urography) less impactful and pose unwarranted risk and significant healthcare costs.

Comparison of the Harms, Advantages, and Costs Associated With Alternative Guidelines for the Evaluation of Hematuria

IMPORTANCE

Existing recommendations for the diagnostic testing of hematuria range from uniform evaluation of varying intensity to patient-level risk stratification. Concerns have been raised about not only the costs and advantages of computed tomography (CT) scans but also the potential harms of CT radiation exposure.

OBJECTIVE

To compare the advantages, harms, and costs associated with 5 guidelines for hematuria evaluation.

DESIGN, SETTING, AND PARTICIPANTS

A microsimulation model was developed to assess each of the following guidelines (listed in order of increasing intensity) for initial evaluation of hematuria: Dutch, Canadian Urological Association (CUA), Kaiser Permanente (KP), Hematuria Risk Index (HRI), and American Urological Association (AUA). Participants comprised a hypothetical cohort of patients (n = 100 000) with hematuria aged 35 years or older. This study was conducted from August 2017 through November 2018.

EXPOSURES

Under the Dutch and CUA guidelines, patients received cystoscopy and ultrasonography if they were 50 years or older (Dutch) or 40 years or older (CUA). Under the KP and HRI guidelines, patients received different combinations of cystoscopy, ultrasonography, and CT urography or no evaluation on the basis of risk factors. Under the AUA guidelines, all patients 35 years or older received cystoscopy and CT urography.

MAIN OUTCOMES AND MEASURES

Urinary tract cancer detection rates, radiation-induced secondary cancers (from CT radiation exposure), procedural complications, false-positive rates per 100 000 patients, and incremental cost per additional urinary tract cancer detected.

RESULTS

The simulated cohort included 100 000 patients with hematuria, aged 35 years or older. A total of 3514 patients had urinary tract cancers (estimated prevalence, 3.5%; 95% CI, 3.0%-4.0%). The AUA guidelines missed detection for the fewest number of cancers (82 [2.3%]) compared with the detection rate of the HRI (116 [3.3%]) and KP (130 [3.7%]) guidelines. However, the simulation model projected 108 (95% CI, 34-201) radiation-induced cancers under the KP guidelines, 136 (95% CI, 62-229) under the HRI guidelines, and 575 (95% CI, 184-1069) under the AUA guidelines per 100 000 patients. The CUA and Dutch guidelines missed detection for a larger number of cancers (172 [4.9%] and 251 [7.1%]) but had 0 radiation-induced secondary cancers. The AUA guidelines cost approximately double the other 4 guidelines ($939/person vs $443/person for Dutch guidelines), with an incremental cost of $1 034 374 per urinary tract cancer detected compared with that of the HRI guidelines.

CONCLUSIONS AND RELEVANCE

In this simulation study, uniform CT imaging for patients with hematuria was associated with increased costs and harms of secondary cancers, procedural complications, and false positives, with only a marginal increase in cancer detection. Risk stratification may optimize the balance of advantages, harms, and costs of CT.

The Investigation of Hematuria

BACKGROUND

Hematuria can be either grossly visible (macrohematuria) or only detectable under a microscope (microhematuria). Microhematuria is often asymptomatic and has a prevalence of 4-5% in routine clinical practice. It may be due to an underlying disease of the kidneys or the urogenital tract. In this article, we provide an overview of the causes of hematuria and of the recommendations of current guidelines for its diagnostic evaluation. A risk-adapted diagnostic strategy for the evaluation of asymptomatic microhematuria (aMH) is presented.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on guidelines from Germany and abroad.

RESULTS

Hematuria has many causes, and a broad urological and nephrological differential diagnosis must be considered. In the absence of high-quality scientific evidence, the recommendations of current guidelines for the diagnostic evaluation of hematuria are not uniform; this is particularly so for aMH. Microhematuria is said to be present when urine microscopy reveals three or more erythrocytes per highpower field. The basic diagnostic evaluation consists of a thorough history and physical examination, measurement of inflammatory parameters and renal function tests, and ultrasonography of the kidneys and bladder. Patients with non-glomerular aMH who have risk factors such as smoking, advanced age, and male sex are more likely to have relevant underlying conditions and should therefore undergo augmented, risk-adapted diagnostic evaluation with urethrocystoscopy, urine cytology, and, when indicated, CT urography. Patients with isolated glomerular hematuria are at elevated risk for renal disease and should undergo follow-up checks at six-month intervals.

CONCLUSION

Although hematuria is common, there is no uniform, internationally accepted, evidence-based algorithm for its diagnostic evaluation. All potential causes of hematuria must be considered, and all individual risk factors taken into account, so that an underlying disease requiring treatment can be identified or ruled out.

Evaluation of Asymptomatic Microscopic Hematuria by Renal Ultrasound to Detect Upper Tract Malignancy: A 20-Year Experience in a Community Hospital

OBJECTIVE

To evaluate the sensitivity of ultrasound imaging in detecting upper urinary tract malignancy in patients with asymptomatic microscopic hematuria (AMH) in an outpatient community setting.

MATERIALS AND METHODS

A list of all patients who received renal ultrasound for hematuria in our health care system between January 1, 1997 and July 1, 2015 was obtained, and electronic health records were retrospectively reviewed. Patients were excluded for age (<18 years), <3 years follow-up, prior upper tract malignancy, recent urinary tract catheterization, inpatient status, pregnancy, insufficient data, or gross hematuria. The initial ultrasound was considered positive if suspicious findings led to a subsequent diagnosis of an upper tract malignancy. False negatives were determined by electronic medical record follow-up for at least 3 years.

RESULTS

Of the 2138 patients with AMH who met inclusion criteria, ultrasound imaging detected suspicious findings in 9 of 9 patients with renal cell carcinoma and 3 of 3 patients with upper tract urothelial cancer, indicating a sensitivity of 100% and 100%, respectively. Four additional malignancies were diagnosed more than 3 years after the initial evaluation for an incidence rate of 1.6 cases of upper tract malignancy per 10,000 person-years.

CONCLUSION

The prevalence of upper urinary tract malignancy was low in patients with AMH. Ultrasonography is an appropriate modality for upper tract imaging in the initial evaluation of patients with AMH. Practice guidelines should be updated to reflect the high sensitivity of ultrasound and low risk of upper tract malignancy in patients with AMH.

Disparities in the diagnostic evaluation of microhematuriaand implications for the detection of urologic malignancy

INTRODUCTION

Disparities in survival for bladder and kidney cancer among the genders and patients with varying insurance coverage have been identified. Microhematuria (MH), a potential early clinical sign of genitourinary malignancy, should prompt a standardized diagnostic evaluation. However, many patients do not complete a full evaluation and may be at risk of a missed or delayed identification of genitourinary pathology.

METHODS

Patients 35 and older with a new diagnosis of MH between 2007 and 2015 were retrospectively identified at a large health system. Our primary outcome of interest was completion of cystoscopy and imaging. Regression modeling was used to assess associations between gender and insurance status with completion of a MH evaluation, adjusted for clinical factors, urinalysis data, and patient demographics.

RESULTS

Of 15,161 patients with MH, only 1,273 patients (8.4%) completed upper tract imaging and a cystoscopy; 899 (5.9%) within 1 year. Median time to imaging was 75days and 68.5days for cystoscopy. Of those with an incomplete evaluation, 23.7% underwent cystoscopy and 76.3% underwent imaging. Male gender, private insurance, and increased MH severity on UA were associated with a complete evaluation. More patients who completed an evaluation were diagnosed with bladder (4.8% vs. 0.3%) and kidney cancer (3.1% vs. 0.4%) when compared to those who did not.

CONCLUSION

Few patients complete a timely evaluation of MH. Women and underinsured patients are disproportionately less likely to complete a work-up for microhematuria and this may have downstream implications for diagnosis.