Peripheral Doses Beyond Electron Applicators in Conventional C-Arm Linear Accelerators: A Systematic Literature Review.

Background: This review investigates peripheral dose levels in electron beam treatments, comparing different manufacturers including Varian, Elekta, and Siemens. Accurate measurement of peripheral dose is vital for patient safety and precise radiation delivery in radiation therapy. Methods: This review followed PRISMA standards, conducting a comprehensive literature search from 1978 to July 2023. Emphasis was on identifying studies analyzing peripheral doses related to various electron beam energies, beam angle, field sizes, cutouts, and applicator combinations. Three major databases including PubMed, Web of Science, and Scopus were searched. Results: A total of 7 articles were included in this review. Strategies such as bolus materials, personalized cutouts, and optimal treatment procedures have all been developed to reduce peripheral radiation exposure and enhance patient safety. Ongoing research in this field is focused on further minimizing the risks associated with out-of-field radiation by improving dose delivery systems. Conclusion: The literature emphasizes importance of precision in electron beam radiation therapy, highlighting the critical need for managing peripheral doses and optimizing hardware to ensure patient safety. It advocates for the use of advanced tools and protocols to maintain a balance between effective treatment while protecting healthy tissues. Continuous research, careful treatment planning, and effective management of peripheral doses are essential.

Radiotherapy planning of spine and pelvis using single-energy metal artifact reduction corrected computed tomography sets.

Metal artifacts produce incorrect Hounsfield units and impact treatment planning accuracy. This work evaluates the use of single-energy metal artifact reduction (SEMAR) algorithm for treatment planning by comparison to manual artifact overriding. CT datasets of in-house 3D-printed spine and pelvic phantoms with and without metal insert(s) and two treated patients with metal implants were analysed. CT number accuracy improved with the use of SEMAR filter: root mean square deviation (RMSD) from reference (without metal) reduced by 35.4 in spine and 98.8 in hip. The plan dose volume histograms (DVHs) and dosimetric measurements showed comparable results. SEMAR reconstruction improved planning efficiency.

The Natural History of Asymptomatic Gallstones: A Longitudinal Study and Prediction Model.

BACKGROUND & AIMS: Despite the high prevalence of asymptomatic gallstones (AGs), there are limited data on their natural history. We aimed to determine the rate of symptom development in a contemporary population, determine factors associated with progression to symptomatic gallstones (SGs), and develop a clinical prediction model. METHODS: We used a retrospective cohort design. The time to first SG was shown using Kaplan-Meier curves. Multivariable competing risk (death) regression analysis was used to identify variables associated with SGs. A prediction model for the development of SGs after 10 years was generated and calibration curves were plotted. Participants were patients with AGs based on ultrasound or computed tomography from the general medical population. RESULTS: From 1996 to 2016, 22,257 patients (51% female) with AGs were identified; 14.5% developed SG with a median follow-up period of 4.6 years. The cumulative incidence was 10.1% (±0.22%) at 5 years, 21.5% (±0.39%) at 10 years, and 32.6% (±0.83%) at 15 years. In a multivariable model, the strongest predictors of developing SGs were female gender (hazard ratio [HR], 1.50; 95% CI, 1.39-1.61), younger age (HR per 5 years, 1.15; 95% CI, 1.14-1.16), multiple stones (HR, 2.42; 95% CI, 2.25-2.61), gallbladder polyps (HR, 2.55; 95% CI, 2.14-3.05), large stones (HR, 2.03; 95% CI, 1.80-2.29), and chronic hemolytic anemia (HR, 1.90; 95% CI, 1.33-2.72). The model showed good discrimination (C-statistic, 0.70) and calibration. CONCLUSIONS: In general medical patients with AGs, symptoms developed at approximately 2% per year. A predictive model with good calibration could be used to inform patients of their risk of SGs.

Echocardiography, lung ultrasound, and cardiac magnetic resonance findings in COVID-19: A systematic review.

BACKGROUND: The manifestations of COVID-19 as outlined by imaging modalities such as echocardiography, lung ultrasound (LUS), and cardiac magnetic resonance (CMR) imaging are not fully described. METHODS: We conducted a systematic review of the current literature and included studies that described cardiovascular manifestations of COVID-19 using echocardiography, CMR, and pulmonary manifestations using LUS. We queried PubMed, EMBASE, and Web of Science for relevant articles. Original studies and case series were included. RESULTS: This review describes the most common abnormalities encountered on echocardiography, LUS, and CMR in patients infected with COVID-19.

An Unusual Case of Acute Hemorrhagic Necrotizing Encephalomyelitis in a COVID-19 Patient.

Acute disseminated encephalomyelitis, also known as ADEM, is a rare autoimmune demyelinating disease of the central nervous system that has been correlated with viral infections and vaccinations and has a range of presentations, where it can present as a mild neurological dysfunction or more severe manifestations ending in chronic neurological sequelae or even death; therefore, it is considered to be a diagnostic challenge. We present a case of ADEM diagnosed in a previously healthy male patient with a recent infection of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Early diagnosis and management with intravenous immunoglobulins held the key to a good outcome.

Bile Cast Nephropathy an Important Biliary Culprit of Kidney Injury.

Bile cast nephropathy (BCN) is a rare form of acute kidney injury (AKI) that occurs in the setting of hyperbilirubinemia. We present the case of a 67 year-old male with severe kidney injury who was found to have obstructive cholestasis. By way of this report, we aim to expand upon the existing literature and showcase the importance of timely endoscopic retrograde cholangio-pancreatography (ERCP) in this setting, in order to prevent irreversible kidney damage.

Meta-analysis of Safety and Efficacy of Anticoagulation versus no Anticoagulation in Octogenarians and Nonagenarians with Atrial Fibrillation.

INTRODUCTION: The role of anticoagulation in octogenarians and nonagenarians with atrial fibrillation (AF) is controversial due to the lack of evidence from randomized controlled trials (RCTs), owing to the under representation of these patients in clinical trials. AIM: In the present meta-analysis we aim at comparing the clinical benefits and risk of anticoagulation (AC) with no AC in octogenarians and nonagenarians. METHODS: We systematically searched MEDLINE/PubMed, EMBASE/Ovid, and Web of Science databases from the inception to October, 2020. Studies were eligible for inclusion if they met the following criteria: studies comparing AC with no AC in patients aged 80 or more for AF and reported thromboembolic events (TE) and bleeding outcomes. We used Mantel-Haenszel method with a Paule-Mandel estimator of Tau2 with Hartung Knapp-Sidik-Jonkman adjustment to estimate risk ratio (RR) with a 95% confidence interval (CI). Outlier analysis was used to adjust for statistical heterogeneity. RESULTS: A total of 10 observation studies and 1 RCT were included in the final analysis. There was no difference in the risk of TE with AC in octogenarians and nonagenarians compared with no AC, before [RR: 0.87, 95% CI 0.62-1.23, I2: 71%, GRADE confidence "very low"] and after [RR: 0.83, 95% CI 0.66-1.04, I2: 55.5%] adjusting for statistical heterogeneity among studies. In the unadjusted analysis, no difference in the risk of bleeding events was observed between both groups [RR: 1.05, 95% CI 0.62-1.77, I2: 86%, GRADE confidence "very low"]. After adjusting for heterogeneity, AC was associated with an increased risk of bleeding compared with those not receiving AC [RR: 1.57, 95% CI 1.44-1.71, I2: 0%]. AC in octogenarians was not associated with a net clinical benefit compared with no AC. CONCLUSIONS: This meta-analysis did not demonstrate any difference in the risk TE in octogenarians and nonagenarians with AF on AC vs. no AC, in both the adjusted and unadjusted analyses. Also, the risk of bleeding events in the unadjusted analysis was similar between both groups. The adjusted analysis showed an increased risk of bleeding in the AC group compared with no AC group. More data is needed to establish safety and efficacy of AC in this vulnerable patient population. The results of this analysis should be interpreted with caution due to the observational nature of most studies included, and the only RCT reported lower rates of TE and similar risk of bleeding.

Application of optical character recognition with natural language processing for large-scale quality metric data extraction in colonoscopy reports.

BACKGROUND AND AIMS: Colonoscopy is commonly performed for colorectal cancer screening in the United States. Reports are often generated in a non-standardized format and are not always integrated into electronic health records. Thus, this information is not readily available for streamlining quality management, participating in endoscopy registries, or reporting of patient- and center-specific risk factors predictive of outcomes. We aim to demonstrate the use of a new hybrid approach using natural language processing of charts that have been elucidated with optical character recognition processing (OCR/NLP hybrid) to obtain relevant clinical information from scanned colonoscopy and pathology reports, a technology co-developed by Cleveland Clinic and eHealth Technologies (West Henrietta, NY, USA). METHODS: This was a retrospective study conducted at Cleveland Clinic, Cleveland, Ohio, and the University of Minnesota, Minneapolis, Minnesota. A randomly sampled list of outpatient screening colonoscopy procedures and pathology reports was selected. Desired variables were then collected. Two researchers first manually reviewed the reports for the desired variables. Then, the OCR/NLP algorithm was used to obtain the same variables from 3 electronic health records in use at our institution: Epic (Verona, Wisc, USA), ProVation (Minneapolis, Minn, USA) used for endoscopy reporting, and Sunquest PowerPath (Tucson, Ariz, USA) used for pathology reporting. RESULTS: Compared with manual data extraction, the accuracy of the hybrid OCR/NLP approach to detect polyps was 95.8%, adenomas 98.5%, sessile serrated polyps 99.3%, advanced adenomas 98%, inadequate bowel preparation 98.4%, and failed cecal intubation 99%. Comparison of the dataset collected via NLP alone with that collected using the hybrid OCR/NLP approach showed that the accuracy for almost all variables was >99%. CONCLUSIONS: Our study is the first to validate the use of a unique hybrid OCR/NLP technology to extract desired variables from scanned procedure and pathology reports contained in image format with an accuracy >95%.

Comparative Effectiveness of Commercial Bowel Preparations in Ambulatory Patients Presenting for Screening or Surveillance Colonoscopy.

BACKGROUND: Inadequate bowel preparation (IBP) is associated with reduced adenoma detection. However, limited research has examined the impact of different commercial bowel preparations (CBPs) on IBP and adenoma detection. We aim to determine whether type of CBP used is associated with IBP or adenoma detection. METHODS: We retrospectively evaluated outpatient, screening or surveillance colonoscopies performed in the Cleveland Clinic health system between January 2011 and June 2017. IBP was defined by the Aronchick scale. Multilevel mixed-effects logistic regression was performed to assess the association between CBP type and IBP and adenoma detection. Fixed effects were defined as demographics, comorbidities, medication use, and colonoscopy factors. Random effect of individual endoscopist was considered. RESULTS: Of 153,639 colonoscopies, 75,874 records met inclusion criteria. Median age was 54; 50% were female; 17.7% had IBP, and adenoma detection rate was 32.6%. In adjusted analyses, compared to GoLYTELY, only NuLYTELY [OR 0.66 (95% CI 0.60, 0.72)] and SuPREP [OR 0.53 (95% CI 0.40, 0.69)] were associated with reduced IBP. Adenoma detection did not vary based on the type of bowel preparation used. CONCLUSIONS: Among patients referred for screening or surveillance colonoscopy, choice of CBP was not associated with adenoma detection. Decisions about CBP should be based on other factors, such as tolerability, cost, or safety.

Custom-designed Small Animal focal iRradiation Jig (SARJ): design, manufacture and dosimetric evaluation.

OBJECTIVE: Preclinical animal models allow testing and refinement of novel therapeutic strategies. The most common preclinical animal irradiators are fixed source cabinet irradiators, which are vastly inferior to clinical linear accelerators capable of delivering highly conformal and precise treatments. The purpose of this study was to design, manufacture and test an irradiation jig (small animal focal irradiation jig, SARJ) that would enable focal irradiation of subcutaneous tumours in a standard fixed source cabinet irradiator. METHODS AND MATERIALS: A lead shielded SARJ was designed to rotate animal holders about the longitudinal axis and slide vertically from the base plate. Radiation dosimetry was undertaken using the built-in ion chamber and GAFChromic RTQA2 and EBT-XD films. Treatment effectiveness was determined by irradiating mice with subcutaneous melanoma lesions using a dose of 36 Gy in three fractions (12 Gy x 3) over three consecutive days. RESULTS: The SARJ was tested for X-ray shielding effectiveness, verification of dose rate, total dose delivered to tumour and dose uniformity. Accurate and uniform delivery of X-ray dose was achieved. X-ray doses were limited to the tumour site when animal holders were rotated around their longitudinal axis to 15o and 195o, allowing sequential dose delivery using parallel-opposed tangential beams. Irradiation of subcutaneous melanoma tumour established on the flanks of mice showed regression. CONCLUSION: SARJ enabled delivery of tangential parallel-opposed radiation beams to subcutaneous tumours in up to five mice simultaneously. SARJ allowed high throughput testing of clinically relevant dose delivery using a standard cabinet-style fixed source irradiator. ADVANCES IN KNOWLEDGE: A custom designed jig has been manufactured to fit into conventional cabinet irradiators and is dosimetrically validated to deliver clinically relevant dose distributions to subcutaneous tumours in mice for preclinical studies.

Modifiable Factors Associated with Quality of Bowel Preparation Among Hospitalized Patients Undergoing Colonoscopy.

INTRODUCTION: Inadequate bowel preparation (IBP) is a common problem in hospitalized patients; however, little is known about how to prevent IBP. In a large, multihospital system, we evaluated the association between modifiable factors and IBP rate. METHODS: We reviewed data from adult (≥18 years) inpatients undergoing colonoscopy between January 2011 and June 2017. Colonoscopies performed in the intensive care unit or lacking descriptions of bowel preparation quality were excluded. Multivariate logistic regression analysis was performed to identify factors associated with IBP. A counterfactual analysis was performed to assess the potential contribution of modifiable factors to IBP. RESULTS: Of 8,819 patients that were included (median age of 64 years; 50.5% female), 51% had IBP. Patients with IBP stayed in the hospital one day longer than those with adequate bowel preparation (P < .001). Modifiable factors associated with IBP include opiate use within three days of colonoscopy (OR, 1.31; 95% CI, 1.18, 1.45), colonoscopy performed after 12:00 pm (OR, 1.25; 95% CI, 1.1, 1.41), and solid diet the day before colonoscopy (OR, 1.37; 95% CI, 1.18, 1.59). In the counterfactual analysis, if all patients avoided these three conditions, adjusted IBP rates were reduced by 5.6%. CONCLUSIONS: Among hospitalized patients undergoing colonoscopy, IBP rates are high and associated with an increased length of stay. Avoiding opiates before colonoscopy, performing colonoscopy before noon, and maintaining patients on a liquid diet or nil per os might significantly reduce IBP rates.

Gallstones: Watch and wait, or intervene?

Gallstones are common in the United States, affecting an estimated 1 in 7 adults. Fortunately, they are asymptomatic in up to 80% of cases, and current guidelines do not recommend cholecystectomy unless they cause symptoms. Laparoscopic cholecystectomy is the standard treatment for symptomatic gallstones, acute cholecystitis, and gallstone pancreatitis.