Clinical Decision Support for Surgery: A Mixed Methods Study on Design and Implementation Perspectives From Urologists.

OBJECTIVE: To assess urologist attitudes toward clinical decision support (CDS) embedded into the electronic health record (EHR) and define design needs to facilitate implementation and impact. With recent advances in big data and artificial intelligence (AI), enthusiasm for personalized, data-driven tools to improve surgical decision-making has grown, but the impact of current tools remains limited. METHODS: A sequential explanatory mixed methods study from 2019 to 2020 was performed. First, survey responses from the 2019 American Urological Association Annual Census evaluated attitudes toward an automatic CDS tool that would display risk/benefit data. This was followed by the purposeful sampling of 25 urologists and qualitative interviews assessing perspectives on CDS impact and design needs. Bivariable, multivariable, and coding-based thematic analysis were applied and integrated. RESULTS: Among a weighted sample of 12,366 practicing urologists, the majority agreed CDS would help decision-making (70.9%, 95% CI 68.7%-73.2%), aid patient counseling (78.5%, 95% CI 76.5%-80.5%), save time (58.1%, 95% CI 55.7%-60.5%), and improve patient outcomes (42.9%, 95% CI 40.5%-45.4%). More years in practice was negatively associated with agreement (P <.001). Urologists described how CDS could bolster evidence-based care, personalized medicine, resource utilization, and patient experience. They also identified multiple implementation barriers and provided suggestions on form, functionality, and visual design to improve usefulness and ease of use. CONCLUSION: Urologists have favorable attitudes toward the potential for clinical decision support in the EHR. Smart design will be critical to ensure effective implementation and impact.

Reduced Aqueous Humor Outflow Pathway Arborization in Childhood Glaucoma Eyes.

Purpose: To compare aqueous humor outflow (AHO) pathway patterns between eyes of childhood glaucoma patients and non-glaucomatous patients receiving cataract surgery. Methods: Aqueous angiography was performed in childhood glaucoma eyes (n = 5) receiving glaucoma surgery and in pediatric (n = 1) and healthy adult (n = 5) eyes receiving cataract surgery. Indocyanine green (0.4%) was introduced into the anterior chamber, and AHO was imaged using an angiographic camera (SPECTRALIS HRA+OCT with Flex Module). Images were acquired and analyzed (ImageJ with Analyze Skeleton 2D/3D plugin) from the nasal sides of the eyes, the usual site of glaucoma angle procedures. Image analysis endpoints included AHO vessel length, maximum vessel length, number of branches, number of branch junctions, and vessel density. Results: Qualitatively, childhood glaucoma eyes demonstrated lesser AHO pathway arborization compared to pediatric and adult eyes without glaucoma. Quantitatively, childhood glaucoma and healthy adult cataract eyes showed similar AHO pathway average branch lengths and maximum branch lengths (P = 0.49-0.99). However, childhood glaucoma eyes demonstrated fewer branches (childhood glaucoma, 198.2 ± 35.3; adult cataract, 506 ± 59.5; P = 0.002), fewer branch junctions (childhood glaucoma, 74.6 ± 13.9; adult cataract, 202 ± 41.2; P = 0.019), and lower vessel densities (childhood glaucoma, 8% ± 1.4%; adult cataract, 17% ± 2.5%; P = 0.01). Conclusions: Childhood glaucoma patients demonstrated fewer distal AHO pathways and lesser AHO pathway arborization. These anatomical alternations may result in a new source of trabecular meshwork-independent AHO resistance in this disease cohort. Translational Relevance: Elevated distal outflow pathway resistance due to decreased AHO pathway arborization may explain some cases of failed trabecular bypass surgery in childhood glaucoma.

A real-time contouring feedback tool for consensus-based contour training.

Purpose: Variability in contouring structures of interest for radiotherapy continues to be challenging. Although training can reduce such variability, having radiation oncologists provide feedback can be impractical. We developed a contour training tool to provide real-time feedback to trainees, thereby reducing variability in contouring. Methods: We developed a novel metric termed localized signed square distance (LSSD) to provide feedback to the trainee on how their contour compares with a reference contour, which is generated real-time by combining trainee contour and multiple expert radiation oncologist contours. Nine trainees performed contour training by using six randomly assigned training cases that included one test case of the heart and left ventricle (LV). The test case was repeated 30 days later to assess retention. The distribution of LSSD maps of the initial contour for the training cases was combined and compared with the distribution of LSSD maps of the final contours for all training cases. The difference in standard deviations from the initial to final LSSD maps, ΔLSSD, was computed both on a per-case basis and for the entire group. Results: For every training case, statistically significant ΔLSSD were observed for both the heart and LV. When all initial and final LSSD maps were aggregated for the training cases, before training, the mean LSSD ([range], standard deviation) was -0.8 mm ([-37.9, 34.9], 4.2) and 0.3 mm ([-25.1, 32.7], 4.8) for heart and LV, respectively. These were reduced to -0.1 mm ([-16.2, 7.3], 0.8) and 0.1 mm ([-6.6, 8.3], 0.7) for the final LSSD maps during the contour training sessions. For the retention case, the initial and final LSSD maps of the retention case were aggregated and were -1.5 mm ([-22.9, 19.9], 3.4) and -0.2 mm ([-4.5, 1.5], 0.7) for the heart and 1.8 mm ([-16.7, 34.5], 5.1) and 0.2 mm ([-3.9, 1.6],0.7) for the LV. Conclusions: A tool that uses real-time contouring feedback was developed and successfully used for contour training of nine trainees. In all cases, the utility was able to guide the trainee and ultimately reduce the variability of the trainee's contouring.

Urologists' Perceptions and Practices Related to Patient Smoking and Cessation: A National Assessment From the 2021 American Urological Association Census.

OBJECTIVE: To assess urologists' perceptions and practices related to smoking and smoking cessation. MATERIALS AND METHODS: Six survey questions were designed to assess beliefs, practices, and determinants related to tobacco use assessment and treatment (TUAT) in outpatient urology clinics. These questions were included in an annual census survey (2021) offered to all practicing urologists. Responses were weighted to represent the practicing US population of nonpediatric urologists (N = 12,852). The primary outcome was affirmative responses to the question, "Do you agree it is important for urologists to screen for and provide smoking cessation treatment to patients in the outpatient clinic?" Practice patterns, perceptions, and opinions of optimal care delivery were assessed. RESULTS: In total, 98% of urologists agreed (27%) or strongly agreed (71%) that cigarette smoking is a significant contributor to urologic disease. However, only 58% agreed that TUAT is important in urology clinics. Most urologists (61%) advise patients who smoke to quit but do not provide additional cessation counseling or medications or arrange follow-up. The most frequently identified barriers to TUAT were lack of time (70%), perceptions that patients are unwilling to quit (44%), and lack of comfort prescribing cessation medications (42%). Additionally, 72% of respondents stated that urologists should provide a recommendation to quit and refer patients for cessation support. CONCLUSION: TUAT does not routinely occur in an evidence-based fashion in outpatient urology clinics. Addressing established barriers and facilitating these practices with multilevel implementation strategies can promote tobacco treatment and improve outcomes for patients with urologic disease.

Electronic Health Record Use and Perceptions among Urologic Surgeons.

OBJECTIVE: Electronic health records (EHRs) have become widely adopted with increasing emphasis on improving care delivery. Improvements in surgery may be limited by specialty-specific issues that impact EHR usability and engagement. Accordingly, we examined EHR use and perceptions in urology, a diverse surgical specialty. METHODS: We conducted a national, sequential explanatory mixed methods study. Through the 2019 American Urological Association Census, we surveyed urologic surgeons on EHR use and perceptions and then identified associated characteristics through bivariable and multivariable analyses. Using purposeful sampling, we interviewed 25 urologists and applied coding-based thematic analysis, which was then integrated with survey findings. RESULTS: Among 2,159 practicing urologic surgeons, 2,081 (96.4%) reported using an EHR. In the weighted sample (n = 12,366), over 90% used the EHR for charting, viewing results, and order entry with most using information exchange functions (59.0-79.6%). In contrast, only 35.8% felt the EHR increases clinical efficiency, whereas 43.1% agreed it improves patient care, which related thematically to information management, administrative burden, patient safety, and patient-surgeon interaction. Quantitatively and qualitatively, use and perceptions differed by years in practice and practice type with more use and better perceptions among more recent entrants into the urologic workforce and those in academic/multispecialty practices, who may have earlier EHR exposure, better infrastructure, and more support. CONCLUSION: Despite wide and substantive usage, EHRs engender mixed feelings, especially among longer-practicing surgeons and those in lower-resourced settings (e.g., smaller and private practices). Beyond reducing administrative burden and simplifying information management, efforts to improve care delivery through the EHR should focus on surgeon engagement, particularly in the community, to boost implementation and user experience.

Patterns of Surgical Management of Male Stress Urinary Incontinence: Data From the AUA Quality Registry.

INTRODUCTION: We examined contemporary patterns in treatment of male stress urinary incontinence and identified predictors of undergoing specific surgical procedures. METHODS: Utilizing the AUA Quality Registry, we identified men with stress urinary incontinence utilizing International Classification of Disease codes and related procedures for stress urinary incontinence performed from 2014 to 2020 utilizing Current Procedural Terminology codes. Characteristics of the patient, surgeon, and practice were included in a multivariate analysis of predictors of management type. RESULTS: We identified 139,034 men with stress urinary incontinence in the AUA Quality Registry, of whom only 3.2% underwent surgical intervention during the study period. Artificial urinary sphincter was the most common procedure with 4,287/7,706 (56%) performed, followed by urethral sling with 2,368/7,706 (31%), and lastly urethral bulking with 1,040/7,706 (13%). There was no significant change by year in volume of each procedure performed during the study period. A large proportion of urethral bulking was performed by a disproportionately small number of practices; 5 high-volume practices performed 54% of the total urethral bulking over the study period. Open surgical procedure was more likely in patients with prior radical prostatectomy, urethroplasty, or care at an academic enter. Urethral bulking was more likely in patients with a history of bladder cancer or care by a surgeon of increasing age or female gender. CONCLUSIONS: Utilization of artificial urinary sphincter and urethral sling now exceeds utilization of urethral bulking for male stress urinary incontinence, though some practices continue to perform a disproportionate volume of bulking. Using data from the AUA Quality Registry, we can identify areas for quality improvement to facilitate guideline-adherent care.

Time Trends and Variation in the Use of Active Surveillance for Management of Low-risk Prostate Cancer in the US.

Importance: Active surveillance (AS) is endorsed by clinical guidelines as the preferred management strategy for low-risk prostate cancer, but its use in contemporary clinical practice remains incompletely defined. Objective: To characterize trends over time and practice- and practitioner-level variation in the use of AS in a large, national disease registry. Design, Setting, and Participants: This retrospective analysis of a prospective cohort study included men with low-risk prostate cancer, defined as prostate-specific antigen (PSA) less than 10 ng/mL, Gleason grade group 1, and clinical stage T1c or T2a, newly diagnosed between January 1, 2014, and June 1, 2021. Patients were identified in the American Urological Association (AUA) Quality (AQUA) Registry, a large quality reporting registry including data from 1945 urology practitioners at 349 practices across 48 US states and territories, comprising more than 8.5 million unique patients. Data are collected automatically from electronic health record systems at participating practices. Exposures: Exposures of interest included patient age, race, and PSA level, as well as urology practice and individual urology practitioners. Main Outcomes and Measures: The outcome of interest was the use of AS as primary treatment. Treatment was determined through analysis of electronic health record structured and unstructured clinical data and determination of surveillance based on follow-up testing with at least 1 PSA level remaining greater than 1.0 ng/mL. Results: A total of 20 809 patients in AQUA were diagnosed with low-risk prostate cancer and had known primary treatment. The median age was 65 (IQR, 59-70) years; 31 (0.1%) were American Indian or Alaska Native; 148 (0.7%) were Asian or Pacific Islander; 1855 (8.9%) were Black; 8351 (40.1%) were White; 169 (0.8%) were of other race or ethnicity; and 10 255 (49.3%) were missing information on race or ethnicity. Rates of AS increased sharply and consistently from 26.5% in 2014 to 59.6% in 2021. However, use of AS varied from 4.0% to 78.0% at the urology practice level and from 0% to 100% at the practitioner level. On multivariable analysis, year of diagnosis was the variable most strongly associated with AS; age, race, and PSA value at diagnosis were all also associated with odds of surveillance. Conclusions and Relevance: This cohort study of AS rates in the AQUA Registry found that national, community-based rates of AS have increased but remain suboptimal, and wide variation persists across practices and practitioners. Continued progress on this critical quality indicator is essential to minimize overtreatment of low-risk prostate cancer and by extension to improve the benefit-to-harm ratio of national prostate cancer early detection efforts.

Insights from the AQUA Registry: a retrospective study of anticholinergic polypharmacy in the United States.

Background: Anticholinergic (ACH) burden is a risk factor for negative health outcomes among older adults. Several medications contribute to ACH burden, including antimuscarinics used to manage overactive bladder (OAB). Objectives: This study aimed to understand the extent of ACH burden in an OAB population in the United States. Design: Non-interventional retrospective analysis. Methods: Adults with OAB whose care providers participated in the American Urological Association Quality (AQUA) Registry between 2014 and 2020 were included in this study. An adapted version of the Pharmacy Quality Alliance (PQA) measure of anticholinergic polypharmacy (poly-ACH) was used to assess ACH burden. The primary outcome was the annual prevalence of poly-ACH, and a secondary outcome was the percentage of patients taking 0, 1, 2, 3, 4, or ⩾ 5 ACH medications by calendar year. Analyses were stratified by age category at diagnosis and sex. Results: The sample comprised 552,840 patients with OAB. The mean age at initial OAB diagnosis was 65.7 years (58.2% male; 57.4% white). Prevalence of poly-ACH was highest in 2015 (3.7%) and lowest in 2020 (1.9%). Patients prescribed no ACH medications made up the largest proportion of each cohort, while those prescribed five or more comprised the smallest. The trend of decreasing proportions of patients taking increasing numbers of ACH medications was consistent. The proportion of patients prescribed no ACH medications increased from 63.3% in 2014 to 74.6% in 2020. The percentage of those prescribed three or more ACHs remained largely unchanged. Poly-ACH was highest among younger individuals (< 65 years of age) and females; temporal trends were similar overall and within each age and sex stratum. Conclusion: In this study, poly-ACH in patients with OAB was relatively infrequent and decreased over the study period. Further evaluation of poly-ACH is needed to assess whether the study findings reflect increased awareness of the negative effects of poly-ACH.

Urology Consult: Association with Renal Trauma Imaging and Intervention.

OBJECTIVE: To describe rates of urology consultation following renal trauma and assess subsequent impact on imaging and intervention. Renal trauma may be initially managed by either trauma or urologic surgeons alone or collaboratively. Differences in management between the specialties are not well studied. METHODS: We conducted an IRB-approved retrospective review of patients at a Level I trauma center sustaining renal trauma between 2014 and 2021. Demographic, injury, radiologic, and intervention variables were extracted. Frequencies and medians were compared using chi-squared and Fischer's exact tests or Mann-Whitney U tests, respectively. Analyses were performed using STATA with P <.05 considered significant. RESULTS: From 2014 to 2021, 118 patients with median age 29 (IQR 22-41) sustained renal trauma. Urology was consulted in 18 (15.3%) cases. Demographic and injury characteristics were similar between the 2 groups. AAST renal injury grade was transcribed in the initial radiologic reports for 49 (41.5%) of patients. Those in the urology consult group were more likely to receive delayed contrast imaging during their admission (50.0% vs 17.0%, P <.01). Among those with high-grade injuries, those with urology consult were less likely to undergo nephrectomy (36.4% vs 78.8%, P = .02). CONCLUSION: We observed differences in imaging patterns between renal trauma patients who are managed primarily by trauma surgery versus urology. However, the impact of these differences in imaging remains to be elucidated. Among patients with high-grade renal trauma, urology consult was associated with decreased rate of nephrectomy, emphasizing the feasibility of renal salvage in a multidisciplinary trauma setting.

An analysis of police transport in an Eastern Association for the Surgery of Trauma multicenter trial examining prehospital procedures in penetrating trauma patients.

BACKGROUND: Police transport (PT) of penetrating trauma patients in urban locations has become routine in certain metropolitan areas; however, whether it results in improved outcomes over prehospital Advanced life support (ALS) transport has not been determined in a multicenter study. We hypothesized that PT would not result in improved outcomes. METHODS: This was a multicenter, prospective, observational study of adults (18+ years) with penetrating trauma to the torso and/or proximal extremity presenting at 25 urban trauma centers. Police transport and ALS patients were allocated via nearest neighbor, propensity matching. Transport mode also examined by Cox regression. RESULTS: Of 1,618 total patients, 294 (18.2%) had PT and 1,324 (81.8%) were by ALS. After matching, 588 (294/cohort) remained. The patients were primarily Black (n = 497, 84.5%), males (n = 525, 89.3%, injured by gunshot wound (n = 494, 84.0%) with 34.5% (n = 203) having Injury Severity Score of 16 or higher. Overall mortality by propensity matching was not different between cohorts (15.6% ALS vs. 15.0% PT, p = 0.82). In severely injured patients (Injury Severity Score ≥16), mortality did not differ between PT and ALS transport (38.8% vs. 36.0%, respectively; p = 0.68). Cox regression analysis controlled for relevant factors revealed no association with a mortality benefit in patients transported by ALS. CONCLUSION: Police transport of penetrating trauma patients in urban locations results in similar outcomes compared with ALS. Immediate transport to definitive trauma care should be emphasized in this patient population. LEVEL OF EVIDENCE: Prognostic and Epidemiologic; Level III.

An Eastern Association for the Surgery of Trauma multicenter trial examining prehospital procedures in penetrating trauma patients.

BACKGROUND: Prehospital procedures (PHP) by emergency medical services (EMS) are performed regularly in penetrating trauma patients despite previous studies demonstrating no benefit. We sought to examine the influence of PHPs on outcomes in penetrating trauma patients in urban locations where transport to trauma center is not prolonged. We hypothesized that patients without PHPs would have better outcomes than those undergoing PHP. METHODS: This was an Eastern Association for the Surgery of Trauma-sponsored, multicenter, prospective, observational trial of adults (18+ years) with penetrating trauma to the torso and/or proximal extremity presenting at 25 urban trauma centers. The impact of PHPs and transport mechanism on in-hospital mortality were examined. RESULTS: Of 2,284 patients included, 1,386 (60.7%) underwent PHP. The patients were primarily Black (n = 1,527, 66.9%) males (n = 1,986, 87.5%) injured by gunshot wound (n = 1,510, 66.0%) with 34.1% (n = 726) having New Injury Severity Score of ≥16. A total of 1,427 patients (62.5%) were transported by Advanced Life Support EMS, 17.2% (n = 392) by private vehicle, 13.7% (n = 312) by police, and 6.7% (n = 153) by Basic Life Support EMS. Of the PHP patients, 69.1% received PHP on scene, 59.9% received PHP in route, and 29.0% received PHP both on scene and in route. Initial scene vitals differed between groups, but initial emergency department vitals did not. Receipt of ≥1 PHP increased mortality odds (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.01-1.83; p = 0.04). Logistic regression showed increased mortality with each PHP, whether on scene or during transport. Subset analysis of specific PHP revealed that intubation (OR, 10.76; 95% CI, 4.02-28.78; p < 0.001), C-spine immobilization (OR, 5.80; 95% CI, 1.85-18.26; p < 0.01), and pleural decompression (OR, 3.70; 95% CI, 1.33-10.28; p = 0.01) had the highest odds of mortality after adjusting for multiple variables. CONCLUSION: Prehospital procedures in penetrating trauma patients impart no survival advantage and may be harmful in urban settings, even when performed during transport. Therefore, PHP should be forgone in lieu of immediate transport to improve patient outcomes. LEVEL OF EVIDENCE: Prognostic, level III.

Significant Management Variability of Urethral stricture Disease in United States: Data from the AUA Quality (AQUA) Registry.

OBJECTIVE: To determine the degree of contemporary practice variation for the treatment of urethral stricture disease (USD) given repeated endoscopic management yields poor long-term success. MATERIALS AND METHODS: The AUA Quality (AQUA) Registry collects data from participating urologists across practice settings by direct interface with local electronic health record systems. We identified procedures used for USD using Current Procedural Terminology (CPT) and International Statistical Classification of Diseases (ICD-9/-10) codes. We assessed the association between patient and provider factors and repeated endoscopic treatment using generalized linear models. Provider details were derived from AUA Census. RESULTS: We identified 20,640 male patients with USD treated surgically in AQUA from 2014-2018. The patients were cared for by 1343 providers at 171 practices, 95% of these community-based. Among patients with USD who had treatment, 20,101(97.9%) underwent endoscopic management. 6218(31%) underwent repeated endoscopic treatment during the study period. Urethroplasty was performed in 539(2.6%) patients.  Median patient age at first procedure for endoscopic surgery vs. urethroplasty was 73 vs. 39 years old, respectively (p<0.001). At the practice level, significant variation in rates of repeated endoscopic management was noted. Patients of older age (OR=1.08, 95%CI: 1.06-1.11 for ages ≥80) and patients with a bladder cancer diagnosis (OR=1.17, 95%CI: 1.15-1.20) had higher odds of receiving repeated endoscopic management. Increasing practitioner age was also associated with increased odds of repeated endoscopic management. (OR=1.13, 95%CI: 1.11- 1.16, for practitioners ≥64). CONCLUSIONS: Repeated endoscopic management for USD is overused. The utilization of endoscopic management is variable across practices and frequently guideline-discordant, presenting an opportunity for quality improvement.

Dependence of Membrane Tether Strength on Substrate Rigidity Probed by Single-Cell Force Spectroscopy.

Substrate rigidity modulates cell mechanics, which affect cell migration and proliferation. Quantifying the effects of substrate rigidity on cancer cell mechanics requires a quantifiable parameter that can be measured for individual cells, as well as a substrate platform with rigidity being the only variable. Here we used single-cell force spectroscopy to pull cancer cells on substrates varying only in rigidity, and extracted a parameter from the force-distance curves to be used to quantify the properties of membrane tethers. Our results showed that tether force increases with substrate rigidity until it reaches its asymptotic limit. The variations are similar for all three cancer cell lines studied, and the largest change occurs in the rigidity regions of softer tissues, indicating a universal response of cancer cell elasticity to substrate rigidity.

Automatic detection of graticule isocenter and scale from kV and MV images.

PURPOSE: To automate the detection of isocenter and scale of the mechanical graticule on kilo-voltage (kV) or mega-voltage (MV) films or electronic portal imaging device (EPID) images. METHODS: We developed a robust image processing approach to automatically detect isocenter and scale of mechanical graticule from digitized kV or MV films and EPID images. After a series of preprocessing steps applied to the digital images, a combination of Hough transform and Radon transform was performed to detect the graticule axes and isocenter. The magnification of the graticule was automatically detected by solving an optimization problem using golden section search and parabolic interpolation algorithm. Tick marks of the graticule were then determined by extending from isocenter along the graticule axes with multiples of the magnification value. This approach was validated using 23 kV films, 26 MV films, and 91 EPID images in different anatomical sites (head-and-neck, thorax, and pelvis). Accuracy was measured by comparing computer detected results with manually selected results. RESULTS: The proposed approach was robust for kV and MV films of varying image quality. The isocenter was detected within 1 mm for 98% of the images. The exceptions were three kV films where the graticule was not actually visible. Of all images with correct isocenter detection, 99% had a magnification detection error less than 1% and tick mark detection error less than 1 mm, with the exception of 1 kV film (magnification error: 3.17%; tick mark error: 1.29 mm) and 1 MV film (magnification error: 0.45%; tick mark error: 1.11 mm). CONCLUSION: We developed an approach to robustly and automatically detect graticule isocenter and scale from two-dimensionla (2D) kV and MV films. This is a first step toward automated treatment planning based on 2D x-ray images.

Mass casualty events: what to do as the dust settles?

Care during mass casualty events (MCE) has improved during the last 15 years. Military and civilian collaboration has led to partnerships which augment the response to MCE. Much has been written about strategies to deliver care during an MCE, but there is little about how to transition back to normal operations after an event. A panel discussion entitled The Day(s) After: Lessons Learned from Trauma Team Management in the Aftermath of an Unexpected Mass Casualty Event at the 76th Annual American Association for the Surgery of Trauma meeting on September 13, 2017 brought together a cadre of military and civilian surgeons with experience in MCEs. The events described were the First Battle of Mogadishu (1993), the Second Battle of Fallujah (2004), the Bagram Detention Center Rocket Attack (2014), the Boston Marathon Bombing (2013), the Asiana Flight 214 Plane Crash (2013), the Baltimore Riots (2015), and the Orlando Pulse Night Club Shooting (2016). This article focuses on the lessons learned from military and civilian surgeons in the days after MCEs.

The impact of mass density variations on an electron Monte Carlo algorithm for radiotherapy dose calculations.

BACKGROUND AND PURPOSE: A key step in electron Monte Carlo dose calculation requires converting Computed Tomography (CT) numbers from a tomographic acquisition to a mass density. This study investigates the dosimetric consequences of perturbations applied to a calibration table between CT number and mass density. MATERIALS AND METHODS: A literature search was performed to define lower and upper bounds for physically reasonable perturbations to a reference CT number to mass density calibration table. Electron beam dose was calculated for ten patients using these variations and the results were compared to clinical plans originally derived with a reference calibration table. Dose differences both globally and in the Planning Target Volume (PTV) were assessed using dose- and volume-based metrics and 3- dimensional gamma analysis for each patient. RESULTS: Small but statistically significant differences were observed between perturbations and reference data for certain metrics including volume of the 50% prescription isodose. Upper and lower variations in CT number to mass density calibration yielded mean values of V50% that were 4.4% larger and 2.1% smaller than reference values respectively. Gamma analysis using 3%/3mm criteria indicated >99% passing rate for the PTV for all patients. Global gamma analysis for some patients showed larger discrepancies possibly due to large electron path lengths through inhomogeneities. CONCLUSIONS: In most patients, physically reasonable perturbations in CT number to mass density curves will not induce clinically significant impact on calculated target dose distributions. Strong dependence of electron transport on voxel material may produce dose speckle throughout the volume. Care should be taken in evaluating critical structures at depths beyond the target volume in highly heterogeneous regions.

Burnout in Urology: Findings from the 2016 AUA Annual Census.

INTRODUCTION: Physician burnout is linked to decreased job performance, increased medical errors, interpersonal conflicts and depression. Two recent multispecialty studies showed that urologists had the highest rate of burnout. However, these reports were limited by a low sample size of urologists (119). We aimed to establish the prevalence of urologist burnout and associated factors. METHODS: In the 2016 American Urological Association Census, Maslach Burnout Inventory questions were randomly assigned to half of the respondents. Using matrix sampling, the 1,126 practicing urologists who received and answered the Maslach Burnout Inventory questions represented the entire 2,301 who completed the census. Burnout was defined as scoring high on the scales of emotional exhaustion or depersonalization. Demographic and practice variables were assessed to establish factors correlating to burnout. RESULTS: Overall 38.8% of urologists met the criteria for burnout, with 17.2% scoring high for emotional exhaustion and 37.1% scoring high for depersonalization. Multivariate analysis revealed that urologist burnout is associated with more patient visits per week, younger age, being in a subspecialty area other than pediatric or oncology, in solo or multispecialty practice, practice size greater than 2 and greater number of work hours per week. CONCLUSIONS: These results suggest that the burnout rate for urologists is lower than previously reported, and are consistent with rates reported in other medical and surgical specialties. However, burnout continues to be an important issue. Greater workload correlated with increased burnout while other practice patterns appeared to be protective. It is critical to keep urologists in the workforce to help lessen projected shortages.

Atlas ranking and selection for automatic segmentation of the esophagus from CT scans.

In radiation treatment planning, the esophagus is an important organ-at-risk that should be spared in patients with head and neck cancer or thoracic cancer who undergo intensity-modulated radiation therapy. However, automatic segmentation of the esophagus from CT scans is extremely challenging because of the structure's inconsistent intensity, low contrast against the surrounding tissues, complex and variable shape and location, and random air bubbles. The goal of this study is to develop an online atlas selection approach to choose a subset of optimal atlases for multi-atlas segmentation to the delineate esophagus automatically. We performed atlas selection in two phases. In the first phase, we used the correlation coefficient of the image content in a cubic region between each atlas and the new image to evaluate their similarity and to rank the atlases in an atlas pool. A subset of atlases based on this ranking was selected, and deformable image registration was performed to generate deformed contours and deformed images in the new image space. In the second phase of atlas selection, we used Kullback-Leibler divergence to measure the similarity of local-intensity histograms between the new image and each of the deformed images, and the measurements were used to rank the previously selected atlases. Deformed contours were overlapped sequentially, from the most to the least similar, and the overlap ratio was examined. We further identified a subset of optimal atlases by analyzing the variation of the overlap ratio versus the number of atlases. The deformed contours from these optimal atlases were fused together using a modified simultaneous truth and performance level estimation algorithm to produce the final segmentation. The approach was validated with promising results using both internal data sets (21 head and neck cancer patients and 15 thoracic cancer patients) and external data sets (30 thoracic patients).

Aeromedical evacuation-relevant hypobaria worsens axonal and neurologic injury in rats after underbody blast-induced hyperacceleration.

BACKGROUND: Occupants of military vehicles targeted by explosive devices often suffer from traumatic brain injury (TBI) and are typically transported by the aeromedical evacuation (AE) system to a military medical center within a few days. This study tested the hypothesis that exposure of rats to AE-relevant hypobaria worsens cerebral axonal injury and neurologic impairment caused by underbody blasts. METHODS: Anesthetized adult male rats were secured within cylinders attached to a metal plate, simulating the hull of an armored vehicle. An explosive located under the plate was detonated, resulting in a peak vertical acceleration force on the plate and occupant rats of 100G. Rats remained under normobaria or were exposed to hypobaria equal to 8,000 feet in an altitude chamber for 6 hours, starting at 6 hours to 6 days after blast. At 7 days, rats were tested for vestibulomotor function using the balance beam walking task and euthanized by perfusion. The brains were then analyzed for axonal fiber injury. RESULTS: The number of internal capsule silver-stained axonal fibers was greater in animals exposed to 100G blast than in shams. Animals exposed to hypobaria starting at 6 hours to 6 days after blast exhibited more silver-stained fibers than those not exposed to hypobaria. Rats exposed to 100% oxygen (O2) during hypobaria at 24 hours postblast displayed greater silver staining and more balance beam foot-faults, in comparison with rats exposed to hypobaria under 21% O2. CONCLUSION: Exposure of rats to blast-induced acceleration of 100G increases cerebral axonal injury, which is significantly exacerbated by exposure to hypobaria as early as 6 hours and as late as 6 days postblast. Rats exposed to underbody blasts and then to hypobaria under 100% O2 exhibit increased axonal damage and impaired motor function compared to those subjected to blast and hypobaria under 21% O2. These findings raise concern about the effects of AE-related hypobaria on TBI victims, the timing of AE after TBI, and whether these effects can be mitigated by supplemental oxygen.