Methodology of thermal drift measurements for surface guided radiation therapy systems and clinical impact assessment illustrated on the C-Rad Catalyst+ HD system.

Thermal drift of optical systems employed for surface guided radiation therapy (SGRT) adds uncertainty to patient setup and monitoring. This work describes methods to measure the drift of individual camera pods as well as the drift of the combined clinical signal. It presents results for four clinical C-Rad Catalyst+ HD systems. Based on the measured clinical drift, recipes are provided on how to calculate relevant uncertainties in patient setup and patient position monitoring with SGRT. Strategies to reduce the impact of drift are explained. While the results are specific to the systems investigated, the methodology is transferable and the clinical recipes are universally applicable.

Updated Guidance on Use and Prioritization of Monoclonal Antibody Therapy for Treatment of COVID-19 in Adolescents.

BACKGROUND: Starting in November 2020, the US Food and Drug Administration (FDA) has issued Emergency Use Authorizations (EUAs) for multiple novel virus-neutralizing monoclonal antibody therapies, including bamlanivimab monotherapy (now revoked), bamlanivimab and etesivimab, casirivimab and imdevimab (REGEN-COV), and sotrovimab, for treatment or postexposure prophylaxis of Coronavirus disease 2019 (COVID-19) in adolescents (≥12 years of age) and adults with certain high-risk conditions. Previous guidance is now updated based on new evidence and clinical experience. METHODS: A panel of experts in pediatric infectious diseases, pediatric infectious diseases pharmacotherapy, and pediatric critical care medicine from 18 geographically diverse US institutions was convened. Through a series of teleconferences and web-based surveys, a guidance statement was developed and refined based on a review of the best available evidence and expert opinion. RESULTS: The course of COVID-19 in children and adolescents is typically mild, though more severe disease is occasionally observed. Evidence supporting risk stratification is incomplete. Randomized controlled trials have demonstrated the benefit of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-specific monoclonal antibody therapies in adults, but data on safety and efficacy in children or adolescents are limited. Potential harms associated with infusion reactions or anaphylaxis are reportedly low in adults. CONCLUSIONS: Based on evidence available as of August 31, 2021, the panel suggests a risk-based approach to administration of SARS-CoV-2 monoclonal antibody therapy. Therapy is suggested for the treatment of mild to moderate COVID-19 in adolescents (≥12 years of age) at the highest risk of progression to hospitalization or severe disease. Therapeutic decision-making about those at moderate risk of severe disease should be individualized. Use as postexposure prophylaxis could be considered for those at the highest risk who have a high-risk exposure but are not yet diagnosed with COVID-19. Clinicians and health systems should ensure safe and timely implementation of these therapeutics that does not exacerbate existing healthcare disparities.

An Assessment of Serological Assays for SARS-CoV-2 as Surrogates for Authentic Virus Neutralization.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 and has since caused a global pandemic resulting in millions of cases and deaths. Diagnostic tools and serological assays are critical for controlling the outbreak, especially assays designed to quantitate neutralizing antibody levels, considered the best correlate of protection. As vaccines become increasingly available, it is important to identify reliable methods for measuring neutralizing antibody responses that correlate with authentic virus neutralization but can be performed outside biosafety level 3 (BSL3) laboratories. While many neutralizing assays using pseudotyped virus have been developed, there have been few studies comparing the different assays to each other as surrogates for authentic virus neutralization. Here, we characterized three enzyme-linked immunosorbent assays (ELISAs) and three pseudotyped vesicular stomatitis virus (VSV) neutralization assays and assessed their concordance with authentic virus neutralization. The most accurate assays for predicting authentic virus neutralization were luciferase- and secreted embryonic alkaline phosphatase (SEAP)-expressing pseudotyped virus neutralizations, followed by green fluorescent protein (GFP)-expressing pseudotyped virus neutralization, and then the ELISAs. IMPORTANCE The ongoing COVID-19 pandemic is caused by infection with severe acute respiratory syndrome virus 2 (SARS-CoV-2). Prior infection or vaccination can be detected by the presence of antibodies in the blood. Antibodies in the blood are also considered to be protective against future infections from the same virus. The "gold standard" assay for detecting protective antibodies against SARS-CoV-2 is neutralization of authentic SARS-CoV-2 virus. However, this assay can only be performed under highly restrictive biocontainment conditions. We therefore characterized six antibody-detecting assays for their correlation with authentic virus neutralization. The significance of our research is in outlining the advantages and disadvantages of the different assays and identifying the optimal surrogate assay for authentic virus neutralization. This will allow for more accurate assessments of protective immunity against SARS-CoV-2 following infection and vaccination.

Ethanol lock therapy in pediatric hematology and oncology.

Central venous catheters are essential for treatment of cancer and hematologic disorders in children. Central line-associated bloodstream infection (CLABSI) is the most common important complication and can lead to serious sequelae. Conventional antibiotic treatment is often unsuccessful. Ethanol lock therapy (ELT) has been shown to prevent CLABSI in various patient groups and might also be beneficial as adjunctive treatment for active infection. Efficacy and safety have not been adequately studied in the pediatric hematology/oncology population. Catheter occlusion and intraluminal clots have been reported. Routine use of ELT should not be recommended in this population until more data are available.