Peer education as a strategy to promote vaccine acceptance: A randomized controlled trial within New York community healthcare practices.

BACKGROUND: Effective strategies are needed to improve vaccine acceptance. This study sought to determine if a peer-led vaccine education intervention embedded within community medical practices increases parental acceptance of pediatric pneumococcal conjugate vaccination. METHODS: From March 2022-July 2023, we conducted a randomized trial at three pediatric health practices in predominantly Hasidic Jewish neighborhoods in New York, where vaccine deferral is common. Parents of children up to 18 months due/overdue for routine pneumococcal vaccination were randomized (1:1) to receive routine care alone or routine care plus a peer educational intervention. Peer educators trained in motivational interviewing and vaccine science provided counseling at enrollment and follow-up telephone engagement in the intervention arm at day 30 and 60. Primary outcome was child's pneumococcal immunization status by allocation arm expressed as at least one dose received between enrollment and 90 days post-enrollment. RESULTS: 144 parent-child dyads were eligible for outcome analysis. Participants in the group receiving routine care along with peer-led vaccine counseling were significantly more likely to have their child receive at least 1 vaccine dose between enrollment and 90 days compared to the group who received routine care alone (28.4 % vs 12.9 %, risk ratio [RR] 2.21, confidence interval [CI] 1.09-4.49, p = 0.022). The effect of peer education was greatest in dyads with children less than 1 year old at enrollment (34 % vs 12.7 %, RR 2.67, CI (1.22-5.86), p = 0.009). CONCLUSIONS: Peer vaccine education can increase vaccine acceptance compared to routine care alone and may be particularly valuable in decreasing vaccination delays for younger infants. (Funded by EGL Charitable Foundation, ClinicalTrials.gov NCT05875779).

Positive Effects of Probiotic Therapy in Patients with Post-Infectious Fatigue.

Post-infectious fatigue is a common complication that can lead to decreased physical efficiency, depression, and impaired quality of life. Dysbiosis of the gut microbiota has been proposed as a contributing factor, as the gut-brain axis plays an important role in regulating physical and mental health. This pilot study aimed to investigate the severity of fatigue and depression, as well as the quality of life of 70 patients with post-infectious fatigue who received a multi-strain probiotic preparation or placebo in a double-blind, placebo-controlled trial. Patients completed questionnaires to assess their fatigue (fatigue severity scale (FSS)), mood (Beck Depression Inventory II (BDI-II)), and quality of life (short form-36 (SF-36)) at baseline and after 3 and 6 months of treatment. Routine laboratory parameters were also assessed, including immune-mediated changes in tryptophan and phenylalanine metabolism. The intervention was effective in improving fatigue, mood, and quality of life in both the probiotic and placebo groups, with greater improvements seen in the probiotic group. FSS and BDI-II scores declined significantly under treatment with both probiotics and placebo, but patients who received probiotics had significantly lower FSS (p < 0.001) and BDI-II (p < 0.001) scores after 6 months. Quality of life scores improved significantly in patients who received probiotics (p < 0.001), while patients taking a placebo only saw improvements in the "Physical limitation" and "Energy/Fatigue" subcategories. After 6 months neopterin was higher in patients receiving placebo, while no longitudinal changes in interferon-gamma mediated biochemical pathways were observed. These findings suggest that probiotics may be a promising intervention for improving the health of patients with post-infectious fatigue, potentially through modulating the gut-brain axis.

How to use direct microscopy for diagnosing fungal infections.

BACKGROUND: Invasive fungal infections are an important cause of morbidity and mortality in a broad range of patients. Adequate and early diagnosis is a challenge and of importance for improved survival. New molecular-based diagnostic methods are trendsetting, yet with the drawback that conventional tests receive less attention, in the laboratory as well as in the clinical setting. OBJECTIVES: We aimed to provide a useful recommendation for direct microscopy for effectively managing numerous specimens related to fungal infections, mainly covering opportunistic pathogens. SOURCES: A PubMed literature search covering direct fungal microscopy was performed with no restrictions on publication dates. CONTENT: Best practise recommendations targeting the role of direct microscopy in diagnosing fungal infections are given. This review highlights when to perform direct microscopy, displays the main fungal morphologies, discusses the pitfalls related to microscopy, and recommends how to best report the results to clinicians. IMPLICATION: In many samples, the performance of direct microscopy provides an important diagnostic benefit that is greater than culture alone. Fluorescent dyes improve sensitivity and allow a fast and rapid read. Reporting includes the presence or absence of yeast forms, septate or non-septate hyphae, pigmentation, cellular location, or any other specific structures being present. The visualization of fungal elements from a sterile body site is proof of an infection, independent of other test reports.

Evaluation of Inoculum Preparation for Etest and EUCAST Broth Dilution to Detect Anidulafungin Polyresistance in Candida glabrata.

The influence of inoculum preparation in EUCAST broth dilution and Etest to detect the coexistence of resistant and susceptible Candida subpopulations (defined as polyresistance [PR]) was evaluated. Cocultures of two echinocandin-resistant and susceptible clinical C. glabrata strains were used to simulate the occurrence of mixed populations in clinical samples, and antifungal susceptibility testing was performed with standard and modified approaches of inoculum preparation. Polyresistant results manifested as microcolonies or double ellipses in Etest and in single reduced optical density (OD) values (dip in OD) in microdilution. The strict inclusion of five distinct colonies of 1:5 and 1:10 resistant and susceptible cocultures led to higher rates of PR and R results compared to including one to two colonies in inoculum preparation (30% and 26% for Etest and broth dilution, respectively). Modifying the inoculum preparation by increasing the turbidity from a 2 to a 4 McFarland standard before redilution to a 0.5 McFarland standard reliably enabled the detection of resistance, with better identification of PR by Etest than by broth dilution (82% versus 32%, respectively) and of resistant minimum inhibitory concentration (MIC) values in 18% of Etests and 67% of microdilutions. The highest identification of PR succeeded with Etest and a modified 3 McFarland standard approach of inoculum preparation. Our data demonstrate that inoculum preparation as recommended and practiced does not reliably identify resistant subpopulations in polyresistant Candida cultures. By increasing the inoculum size for Etest assays from a 2 to a 4 McFarland standard with subsequent redilution, we propose a simple adaptation to increase reliability.

Multiple colony antifungal susceptibility testing detects polyresistance in clinical Candida cultures: a European Confederation of Medical Mycology excellence centers study.

OBJECTIVES: Many factors influence the outcome of in vitro antifungal susceptibility testing (AFST), including endpoint definition, inoculum sizes, time and temperature of incubation, and growth medium used. This European Confederation of Medical Mycology (ECMM) Excellence center driven study investigated multiple colony testing (MCT) of five separate colonies to investigate the prevalence of polyresistance (PR), defined as heterogeneous MICs from a same-species Candida culture irrespective of the underlying resistance mechanism. METHODS: Candida spp. MCT for fluconazole and anidulafungin was performed by Etest prospectively comprising 405 clinical samples. MCT results were compared to the real-life routine MIC data and PR was assessed. Candida colonies displaying strong PR were selected for genotyping using multilocus sequence typing and random amplified polymorphic DNA assays for C. lusitaniae. RESULTS: Candida PR was observed in 33 of 405 samples (8.1%), with higher rates for non-albicans species (26/186, 14%) than for C. albicans (7/219, 3.2%), and for fluconazole than for anidulafungin. MCT detected acquired resistance more often than routine AFST (18/405, 4.5%) and 9 of the 161 investigated blood cultures showed PR (5.6%). Multilocus sequence typing and random amplified polymorphic DNA did not reveal a uniform genetic correlate in strains studied. CONCLUSIONS: This study shows that Candida single MIC-values obtained in routine diagnostics may be incidental, as they fail to detect PR and resistant subpopulations reliably. The reasons for PR seem to be manifold and should be regarded as a phenotypical expression of genomic variability irrespective of the underlying resistance mechanism, which may help to interpret ambiguous and non-reproducible AFST results.

Sepsis in Pediatric Cancer: Does Gender Matter? A 20-Year Retrospective Study.

INTRODUCTION: Gender plays an active role in the incidence and outcome of many infectious and malignant diseases. However, there is still no study examining sex differences for developing bloodstream infections (BSIs) in pediatric patients with cancer. We sought to identify potential gender-specific risk factors for BSIs. METHODS: Data were retrospectively analyzed from 621 pediatric patients treated for childhood cancer in a tertiary single center between 1 January 2000 and 31 June 2018. After central venous access device (CVAD) placement, patients were followed up until CVAD was removed or at the most for 1 year. We calculated the gender-specific prevalence for BSIs and compared the causative bacterial strains. RESULTS: Of 621 pediatric patients with cancer (283 girls [45.6%] and 338 boys [54.4%]), 110 patients (41 girls [37.3%] and 69 boys [62.7%]) were identified with a total of 134 BSIs. Girls and boys had a similar incidence for BSI (13%) within the first 3 months of therapy, after which the risk for BSI increased significantly for boys (34% versus 21%, boys versus girls, P = 0.025). Moreover, BSI with gram-positive bacteria affected boys nearly twice as often as girls (29.8% versus 56.5%, girls versus boys). CONCLUSIONS: Future clinical awareness of hygiene-related BSIs in boys could be helpful in identifying areas for improvement.

What We Learn from Surveillance of Microbial Colonization in Recipients of Pediatric Hematopoietic Stem Cell Transplantation.

Infections in hematopoietic stem cell transplant (HSCT) remain one of the major causes for morbidity and mortality, and it is still unclear whether knowledge of microbial colonization is important. In this single-center study, we collected weekly surveillance cultures in pediatric recipients of allogenic HSCT from five different body regions and tested for bacteria and fungi. Between January 2010 and December 2021, we collected 1095 swabs from 57 recipients of allogeneic HSCTs (median age: 7.5 years, IQR 1−3: 2.5−11.9). The incidence of positive microbiological cultures (n = 220; 20.1%) differed according to the anatomic localization (p < 0.001) and was most frequent in the anal region (n = 98), followed by the genital, pharyngeal and nasal regions (n = 55, n = 37 and n = 16, respectively). Gram-positive bacteria (70.4%) were the most commonly isolated organisms, followed by fungi (18.6%), Gram-negative (5.5%), non-fermenting bacteria (1.4%), and other flora (4.1%). No association with increased risk of infection (n = 32) or septicemia (n = 7) was noted. Over time, we did not observe any increase in bacterial resistance. We conclude that there is no benefit to surveillance of microbial colonization by culture-based techniques in pediatric HSCT. Sequencing methods might enhance the detection of pathogens, but its role is still to be defined.

A Laboratory-Based Study on Multiple Biomarker Testing in the Diagnosis of COVID-19-Associated Pulmonary Aspergillosis (CAPA): Real-Life Data.

(1) Background: Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) raises concerns to contribute to an increased mortality. The incidence of CAPA varies widely within hospitals and countries, partly because of difficulties in obtaining a reliable diagnosis. (2) Methods: Here, we assessed Aspergillus culture-positive and culture-negative respiratory tract specimens via direct fungal microscopy (gold standard) and compared the results with galactomannan enzyme immunoassay (GM-EIA) and Aspergillus PCR. (3) Results: 241 respiratory samples from patients suffering from SARS-CoV-2 pneumonia were evaluated. Results showed both diagnostic tools, Aspergillus PCR and GM-EIA, to be positive or negative displaying a sensitivity of 0.90, a specificity of 0.77, a negative predictive value (NPV) of 0.95, and a positive predictive value (PPV) of 0.58 in Aspergillus sp. culture and microscopic-positive specimens. Non-bronchoalveolar lavage (BAL) samples, obtained within a few days from the same patient, showed a high frequency of intermittent positive or negative GM-EIA or Aspergillus PCR results. Positivity of a single biomarker is insufficient for a proper diagnosis. A broad spectrum of Aspergillus species was detected. (4) Conclusions: Our study highlights the challenges of combined biomarker testing as part of diagnosing CAPA. From the results presented, we highly recommend the additional performance of direct microscopy in respiratory specimens to avoid overestimation of fungal infections by applying biomarkers.

Culture-Free Detection of Antibiotic Resistance Markers from Native Patient Samples by Hybridization Capture Sequencing.

The increasing incidence of antimicrobial resistance (AMR) is a major global challenge. Routine techniques for molecular AMR marker detection are largely based on low-plex PCR and detect dozens to hundreds of AMR markers. To allow for comprehensive and sensitive profiling of AMR markers, we developed a capture-based next generation sequencing (NGS) workflow featuring a novel AMR marker panel based on the curated AMR database ARESdb. Our primary objective was to compare the sensitivity of target enrichment-based AMR marker detection to metagenomics sequencing. Therefore, we determined the limit of detection (LOD) in synovial fluid and urine samples across four key pathogens. We further demonstrated proof-of-concept for AMR marker profiling from septic samples using a selection of urine samples with confirmed monoinfection. The results showed that the capture-based workflow is more sensitive and requires lower sequencing depth compared with metagenomics sequencing, allowing for comprehensive AMR marker detection with an LOD of 1000 CFU/mL. Combining the ARESdb AMR panel with 16S rRNA gene sequencing allowed for the culture-free detection of bacterial taxa and AMR markers directly from septic patient samples at an average sensitivity of 99%. Summarizing, the newly developed ARESdb AMR panel may serve as a valuable tool for comprehensive and sensitive AMR marker detection.

Genomic and Phenotypic Analysis of Linezolid-Resistant Staphylococcus epidermidis in a Tertiary Hospital in Innsbruck, Austria.

Whole genome sequencing is a useful tool to monitor the spread of resistance mechanisms in bacteria. In this retrospective study, we investigated genetic resistance mechanisms, sequence types (ST) and respective phenotypes of linezolid-resistant Staphylococcus epidermidis (LRSE, n = 129) recovered from a cohort of patients receiving or not receiving linezolid within a tertiary hospital in Innsbruck, Austria. Hereby, the point mutation G2603U in the 23S rRNA (n = 91) was the major resistance mechanism followed by the presence of plasmid-derived cfr (n = 30). The majority of LRSE isolates were ST2 strains, followed by ST5. LRSE isolates expressed a high resistance level to linezolid with a minimal inhibitory concentration of ≥256 mg/L (n = 83) in most isolates, particularly in strains carrying the cfr gene (p < 0.001). Linezolid usage was the most prominent (but not the only) trigger for the development of linezolid resistance. However, administration of linezolid was not associated with a specific resistance mechanism. Restriction of linezolid usage and the monitoring of plasmid-derived cfr in LRSE are potential key steps to reduce linezolid resistance and its transmission to more pathogenic Gram-positive bacteria.

Current Social Media Use Among Radiation Oncology Trainees.

PURPOSE: Resident physicians use social media (SM) for many reasons. We sought to characterize current SM use by radiation oncology (RO) trainees for education and professional development. METHODS AND MATERIALS: An anonymous 40-question survey was sent by e-mail to RO residents in the 2018 to 2019 academic year. SM platform use, time spent on SM, professional use, and opinions regarding SM use were assessed. Descriptive statistics and a univariate logistic regression analysis were performed to identify factors associated with perceptions of SM and spending >25% of SM time for academic or professional purposes. RESULTS: Of the 615 residents surveyed, 149 responded (24% response rate). Facebook (73%), theMednet (62%), Instagram (59%), Twitter (57%), and Doximity (50%) were the top SM platforms used. Most respondents (53%) reported <25% of overall SM time on professional/academic purposes, and 21% reported using SM >60 minutes per day over the past week. Residents with an RO mentor on SM (n = 35; 24%; odds ratio [OR]: 2.79; 95% confidence interval [CI], 1.29-6.08; P = .010), those participating in RO discussions on SM (n = 71; 48%; OR: 2.85; 95% CI, 1.42-5.72; P = .003), and those interacting with professional societies (n = 69; 46%; OR: 7.11; 95% CI, 3.32-15.24; P < .001) were more likely to spend >25% of their SM time on professional/academic purposes. The vast majority of respondents agreed that SM exposed them to novel educational content (82%) and was helpful for career development (65%). In addition, 69% agreed that SM can improve clinical skills and knowledge. A substantial minority agreed that SM distracts them from studying (38%) or they felt pressure to have a SM presence (29%). CONCLUSIONS: Most RO residents reported that SM provides novel educational content and can help with career development. Potential disadvantages of SM for trainees may include distraction and pressure to maintain a SM presence. SM use by RO trainees merits further research to optimize its potential for education and professional development.

Which Type of Empiric Antibiotic Therapy is Appropriate? A 20-Year Retrospective Study of Bloodstream Infections in Childhood Cancer.

INTRODUCTION: Sufficient empirical antimicrobial therapy in febrile patients with cancer is challenging, owing to the limited arsenal of available antibiotics in an era of growing resistance. Because of the emergence of gram-negative bacteria resistant to ceftazidime and piperacillin, a combination antibiotic therapy was employed that uses meropenem combined with gentamicin and/or vancomycin if the patient further deteriorates. METHODS: A retrospective cohort analysis was performed including all patients with catheter-associated bloodstream infections (BSIs) and treated for childhood cancer in a tertiary single centre between 1 January 2000 and 31 June 2018. We calculated the prevalence and the risk for BSIs and compared the in vitro susceptibility to various antimicrobial agents. RESULTS: Of 653 patients with childhood cancer, 113 patients (17.3%) were identified with a total of 139 BSIs, most of them occurring in patients with leukaemia (n = 90, 64.7%) and were associated with gram-positive bacteria (60.5%). In our cohort, all BSIs with gram-negative bacteria exhibited in vitro susceptibility against meropenem alone without any signs of resistance development. The antibiotic coverage of our meropenem-based combination therapy was also highly effective for gram-positive and non-fermenting bacteria. Thus, BSI-related mortality in all 139 BSI episodes was 1.4%. Clostridium difficile infections (CDIs), as main adverse event of carbapenem usage, occurred in only 16 (2.5%) patients. CONCLUSION: Our meropenem-based combination therapy showed sufficient empirical antibiotic coverage in the majority of BSIs (96.4%) and did not result in an increased rate of unwanted side effects or development of antibiotic resistance.

Serology anno 2021-fungal infections: from invasive to chronic.

BACKGROUND: Diagnosing invasive or chronic fungal infections is a challenge, particularly in the immunocompromised host. Microscopy and culture remain the reference standard, but are insensitive. The use of non-culture-based techniques is recommended in conjunction with conventional methods to improve the diagnostic yield. OBJECTIVES: The aim was to provide an updated 2021 inventory of fungal antigen and serology tests for diagnosing invasive and chronic fungal infections, the key focus was set on Aspergillus, Candida and Cryptococcus species. SOURCES: Pubmed search for publications with the key words fungal antigen tests, laboratory-based diagnosis of invasive pulmonary aspergillosis, chronic pulmonary aspergillosis, invasive candidiasis, invasive fungal infections and cryptococcal infections published from 2017 to 2020. CONTENT: Antigen assays such as the galactomannan (GM) and ß-d-glucan detection systems are frequently used, but these tests vary in sensitivity and specificity, depending on the patient population involved, specimens inspected, cut-offs defined, test strategy applied and inclusion or exclusion of possible fungal case definitions. Multiple different detection systems are available, with recently introduced new point-of-care tests such as the lateral flow device and the lateral flow assay. Despite a wide heterogeneity in populations evaluated, studies indicate a better diagnostic performance of bronchoalveolar lavage GM in comparison with serum GM, and a suboptimal specificity of GM bronchoalveolar lavages (cut-off ≥1) and serum ß-d-glucan in non-neutropenic individuals. Point-of-care cryptococcal antigen tests show excellent performance. IMPLICATIONS: There are fungal antigen detection tests available with excellent to reasonable clinical performance to diagnose invasive fungal infections. Only a few assays are useful to monitor therapeutic response. There are multiple marketed IgG antibody tests to detect Aspergillus fumigatus antibodies, the titres vary widely and the performance differs significantly. In general, diagnostic tests are vulnerable to being affected by the host, the microbe and laboratory setting.

Rapid Antifungal Susceptibility Testing of Yeasts and Molds by MALDI-TOF MS: A Systematic Review and Meta-Analysis.

Due to the growing burden of fungal infections and a recent rise in antifungal resistance, antifungal susceptibility testing (AFST) is of increasing importance. The common methods of AFST have turnaround times of 24 to 48 h, and the available rapid methods are limited by applicability, cost-efficiency or accuracy. Given the urgency of adequate antifungal treatment in invasive mycoses, the need for the rapid and reliable detection of resistance is evident. In this systematic review and meta-analysis, we evaluated the diagnostic accuracy of AFST based on matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Twelve studies were reviewed, and data for the comparative analysis of their accuracy and methodology were systematically extracted. Compared to broth dilution as the gold standard, MALDI-TOF MS-based AFST reached a pooled sensitivity and specificity of 91% (95% Confidence Interval [CI], 84% to 96%) and 95% (95% CI, 90% to 98%), respectively. A comparative analysis showed that the sensitivity was higher for the semi-quantitative matrix-assisted laser desorption ionization Biotyper antibiotic susceptibility test rapid assay (MBT ASTRA) technique (96%) than for the correlate composite index (CCI) approach (85%), which is based on spectrum changes. Turnaround times below eight hours reached better diagnostic values than longer incubation periods, qualifying MALDI-TOF MS-based AFST as a rapid and accurate method for the detection of antifungal resistance.

Evaluating Bias in Speaker Introductions at the American Society for Radiation Oncology Annual Meeting.

PURPOSE: Introducing a physician without a professional title may reinforce bias in medicine by influencing perceived credibility. We evaluated differences in the use of professional titles in introductions of speakers at recent American Society for Radiation Oncology (ASTRO) Annual Meetings. METHODS AND MATERIALS: We reviewed recordings from the 2017 to 2019 ASTRO Annual Meetings and included complete introductions of speakers with a doctoral degree. Professional introduction was defined as "Doctor" or "Professor" followed by the speaker's full or last name. We collected use of professional introduction, introducer gender, speaker gender, and speaker professional and demographic variables. Identified speakers were sent surveys to collect self-reported demographic data. Analysis was performed using χ2 tests and multivariable logistic regression (MVA). RESULTS: Of 3267 presentations reviewed, 1226 (38%) met the inclusion criteria. Overall, 805 (66%) speakers and 710 (58%) introducers were men. Professional introductions were used in 74% (2017), 71% (2018), and 69% (2019) of the presentations. There was no difference in the use of professional introductions for male and female speakers (71% vs 73%; P = .550). On MVA, male introducers were associated with decreased use of professional address (odds ratio [OR], 0.36; 95% confidence interval [CI], 0.26-0.49; P < .001). At the 2019 conference, professional introduction was less likely to be used (2019 vs 2017: OR, 0.68; 95% CI, 0.49-0.96; P = 0.026). Those who self-identified as Asian/Pacific Islander were twice as likely to receive a professional introduction compared with those who identified as white (OR, 1.95; 95% CI, 1.07-3.64; P = .033). CONCLUSION: Male introducers were significantly less likely to introduce any speaker, regardless of gender, by their professional title, and overall use of professional introductions decreased from 2017 to 2019. Furthermore, no difference in professional introduction use by speaker gender was identified at the recent ASTRO meetings. Implementing speaker guidelines could increase the use of professional introductions and raise awareness of unconscious bias at future ASTRO meetings.

#ThisIsBrachytherapy: Increasing awareness of brachytherapy.

PURPOSE: The use of brachytherapy continues to be a vital application of radiation oncology for various cancers. Despite this, there has been a decrease in the utilization of brachytherapy in many cancers. Social media in medicine facilitates engagement and advocacy. We launched a social media campaign to bring awareness of brachytherapy throughout the world with #ThisIsBrachytherapy hashtag on July 17, 2019. METHODS AND MATERIALS: #ThisIsBrachytherapy hashtag was registered with Symplur Healthcare Hashtag Project. We collected total tweet counts, retweet counts, impression counts, geolocation, top 10 influencers, associated hashtags, associated words, and word sentiment score. RESULTS: The campaign launched on July 17, 2019, had a total of 145 tweets on that day with 213,416 impressions. Twenty-seven accounts (45%) were identified as physicians. Top countries which tweeted, among those with information available, included the United States, United Kingdom, and Australia. Since July 17, 2019, there has been an increase in tweets using #ThisIsBrachytherapy, with 1990 total tweets with 1,999,248 impressions. Fifty-four percent (1030) of the tweets contained photos and 319 contained links. This was from 462 unique users. Word sentiment was overwhelmingly positive. Associated hashtags with #ThisIsBrachytherapy included most commonly #radonc, #brachytherapy, #brachy, #prostatecancer, and #pcsm. CONCLUSIONS: The #ThisIsBrachytherapy inaugural campaign was successful and has continued to grow throughout the months after the initiation. By continuing to advocate for brachytherapy through the social media campaign #ThisIsBrachytherapy, we can empower radiation oncologists, especially trainees, and patients to address underutilization.

A Portrait of Current Radiation Oncology Twitter Influencers.

Introduction We aimed to characterize the most influential radiation oncologists on Twitter, the correlation between their Twitter activity and their academic profiles as measured by the Scopus H-index as well as their activity around the American Society for Radiation Oncologists (ASTRO) 2018 meeting. Methods We defined radiation oncology influencers as any radiation oncologist with 500 or more followers on Twitter through the first two weeks of August 2019. We collected their available characteristics, their Scopus H-index, and Twitter metrics. We examined their general Twitter activity as well as their specific activity before, during, and after the 2018 ASTRO annual meeting. We identified the most frequent tweet content categories for each influencer. Results We identified 48 radiation oncologist influencers; 79% were male, 75% were based in the United States, and 94% were affiliated with an academic center. Among them, 44% had high H-indices of ≥21, an average value in academic faculty for full professors or department heads. There were no correlations between H-index and Twitter metrics such as the number of individuals the influencer was following (p = 0.58), the number of followers (p = 0.66), the number of tweets (p = 0.88), and the number of likes (p = 0.54). During the period around ASTRO 2018, the mean number of tweets per influencer was 4437 (range 87-93,000). Conclusion Current radiation oncology influencers are predominantly North American males from academic institutions. A correlation between academic productivity as measured by the H-index and Twitter metrics was not demonstrated. The fact that some influencers had a low H-index supports that a high academic profile as measured by traditional metrics is not necessary to have a voice in the Twitter radiation oncology community.