RESUMEN
Concern over democratic erosion has led to a proliferation of proposed interventions to strengthen democratic attitudes in the United States. Resource constraints, however, prevent implementing all proposed interventions. One approach to identify promising interventions entails leveraging domain experts, who have knowledge regarding a given field, to forecast the effectiveness of candidate interventions. We recruit experts who develop general knowledge about a social problem (academics), experts who directly intervene on the problem (practitioners), and nonexperts from the public to forecast the effectiveness of interventions to reduce partisan animosity, support for undemocratic practices, and support for partisan violence. Comparing 14,076 forecasts submitted by 1,181 forecasters against the results of a megaexperiment (n = 32,059) that tested 75 hypothesized effects of interventions, we find that both types of experts outperformed members of the public, though experts differed in how they were accurate. While academics' predictions were more specific (i.e., they identified a larger proportion of ineffective interventions and had fewer false-positive forecasts), practitioners' predictions were more sensitive (i.e., they identified a larger proportion of effective interventions and had fewer false-negative forecasts). Consistent with this, practitioners were better at predicting best-performing interventions, while academics were superior in predicting which interventions performed worst. Our paper highlights the importance of differentiating types of experts and types of accuracy. We conclude by discussing factors that affect whether sensitive or specific forecasters are preferable, such as the relative cost of false positives and negatives and the expected rate of intervention success.
Asunto(s)
Problemas Sociales , Estados Unidos , PredicciónRESUMEN
There is substantial concern about democratic backsliding in the United States. Evidence includes notably high levels of animosity toward out-partisans and support for undemocratic practices (SUP) among the general public. Much less is known, however, about the views of elected officials-even though they influence democratic outcomes more directly. In a survey experiment conducted with state legislators (N = 534), we show that these officials exhibit less animosity toward the other party, less SUP, and less support for partisan violence (SPV) than the general public. However, legislators vastly overestimate the levels of animosity, SUP, and SPV among voters from the other party (though not among voters from their own party). Further, those legislators randomly assigned to receive accurate information about the views of voters from the other party reported significantly lower SUP and marginally significantly lower partisan animosity toward the other party. This suggests that legislators' democratic attitudes are causally linked to their perceptions of other-party voters' democratic attitudes. Our findings highlight the importance of ensuring that office holders have access to reliable information about voters from both parties.
RESUMEN
Mechanophores are molecular motifs that respond to mechanical perturbance with targeted chemical reactions toward desirable changes in material properties. A large variety of mechanophores have been investigated, with applications focusing on functional materials, such as strain/stress sensors, nanolithography, and self-healing polymers, among others. The responses of engineered mechanophores, such as light emittance, change in fluorescence, and generation of free radicals (FRs), have potential for bioimaging and therapy. However, the biomedical applications of mechanophores are not well explored. Herein, we report an in vitro demonstration of an FR-generating mechanophore embedded in biocompatible hydrogels for noninvasive cancer therapy. Controlled by high-intensity focused ultrasound (HIFU), a clinically proven therapeutic technique, mechanophores were activated with spatiotemporal precision to generate FRs that converted to reactive oxygen species (ROS) to effectively kill tumor cells. The mechanophore hydrogels exhibited no cytotoxicity under physiological conditions. Upon activation with HIFU sonication, the therapeutic efficacies in killing in vitro murine melanoma and breast cancer tumor cells were comparable with lethal doses of H2O2 This process demonstrated the potential for mechanophore-integrated HIFU combination as a noninvasive cancer treatment platform, named "mechanochemical dynamic therapy" (MDT). MDT has two distinct advantages over other noninvasive cancer treatments, such as photodynamic therapy (PDT) and sonodynamic therapy (SDT). 1) MDT is ultrasound based, with larger penetration depth than PDT. 2) MDT does not rely on sonosensitizers or the acoustic cavitation effect, both of which are necessary for SDT. Taking advantage of the strengths of mechanophores and HIFU, MDT can provide noninvasive treatments for diverse cancer types.
Asunto(s)
Fenómenos Biomecánicos , Biopolímeros/química , Hidrogeles/química , Ondas Ultrasónicas , Animales , Compuestos Azo/química , Humanos , Hidrogeles/síntesis química , Melanoma Experimental , Ratones , Neoplasias/terapia , Polietilenglicoles/química , Especies Reactivas de Oxígeno/química , Especies Reactivas de Oxígeno/metabolismo , Termodinámica , Terapia por Ultrasonido/métodosRESUMEN
Both neuronal and genetic mechanisms regulate brain function. While there are excellent methods to study neuronal activity in vivo, there are no nondestructive methods to measure global gene expression in living brains. Here, we present a method, epigenetic MRI (eMRI), that overcomes this limitation via direct imaging of DNA methylation, a major gene-expression regulator. eMRI exploits the methionine metabolic pathways for DNA methylation to label genomic DNA through 13C-enriched diets. A 13C magnetic resonance spectroscopic imaging method then maps the spatial distribution of labeled DNA. We validated eMRI using pigs, whose brains have stronger similarity to humans in volume and anatomy than rodents, and confirmed efficient 13C-labeling of brain DNA. We also discovered strong regional differences in global DNA methylation. Just as functional MRI measurements of regional neuronal activity have had a transformational effect on neuroscience, we expect that the eMRI signal, both as a measure of regional epigenetic activity and as a possible surrogate for regional gene expression, will enable many new investigations of human brain function, behavior, and disease.
Asunto(s)
Encéfalo/metabolismo , Metilación de ADN , Epigénesis Genética , Imagen por Resonancia Magnética/métodos , Animales , Encéfalo/diagnóstico por imagen , Isótopos de Carbono/metabolismo , Espectroscopía de Resonancia Magnética con Carbono-13 , Humanos , Metionina/administración & dosificación , Reproducibilidad de los Resultados , PorcinosRESUMEN
Containing the COVID-19 pandemic in the United States requires mobilizing a large majority of the mass public to vaccinate, but many Americans are hesitant or opposed to vaccination. A significant predictor of vaccine attitudes in the United States is religiosity, with more-religious individuals expressing more distrust in science and being less likely to get vaccinated. Here, we test whether explicit cues of common religious identity can help medical experts build trust and increase vaccination intentions. In a preregistered survey experiment conducted with a sample of unvaccinated American Christians (n = 1,765), we presented participants with a vaccine endorsement from a prominent medical expert (NIH Director Francis Collins) and a short essay about doctors' and scientists' endorsement of the vaccines. In the common religious identity condition, these materials also highlighted the religious identity of Collins and many medical experts. Unvaccinated Christians in the common identity condition expressed higher trust in medical experts, greater intentions to vaccinate, and greater intentions to promote vaccination to friends and family than those who did not see the common identity cue. These effects were moderated by religiosity, with the strongest effects observed among the most religious participants, and statistically mediated by heightened perceptions of shared values with the medical expert endorsing the vaccine. These findings demonstrate the efficacy of common identity cues for promoting vaccination in a vaccine-hesitant subpopulation. More generally, the results illustrate how trust in science can be built through the invocation of common group identities, even identities often assumed to be in tension with science.
Asunto(s)
Señales (Psicología) , Personal de Salud , Intención , Religión , Confianza , Vacunación , Vacunas contra la COVID-19/inmunología , Humanos , Estados UnidosRESUMEN
Overcoming the COVID-19 pandemic requires motivating the vast majority of Americans to get vaccinated. However, vaccination rates have become politically polarized, and a substantial proportion of Republicans have remained vaccine hesitant for months. Here, we explore how endorsements by party elites affect Republicans' COVID-19 vaccination intentions and attitudes. In a preregistered survey experiment (n = 1,480), we varied whether self-identified Republicans saw endorsements of the vaccine from prominent Republicans (including video of a speech by former President Donald Trump), from the Democratic Party (including video of a speech by President Joseph Biden), or a neutral control condition including no endorsements. Unvaccinated Republicans who were exposed to the Republican elite endorsement reported 7.0% higher vaccination intentions than those who viewed the Democratic elite endorsement and 5.7% higher than those in the neutral control condition. These effects were statistically mediated by participants' reports of how much they thought Republican politicians would want them to get vaccinated. We also found evidence of backlash effects against Democratic elites: Republicans who viewed the Democratic elite endorsement reported they would be significantly less likely to encourage others to vaccinate and had more negative attitudes toward the vaccine, compared with those who viewed the Republican elite endorsement or the neutral control. These results demonstrate the relative advantage of cues from Republican elites-and the risks of messaging from Democrats currently in power-for promoting vaccination among the largest vaccine-hesitant subgroup in the United States.
Asunto(s)
Señales (Psicología) , Política , Vacunación/psicología , Actitud , COVID-19/epidemiología , COVID-19/prevención & control , Humanos , Intención , SARS-CoV-2 , Encuestas y Cuestionarios , Estados UnidosRESUMEN
Detecting metal ions in vivo with a high spatiotemporal resolution is critical to understanding the roles of the metal ions in both healthy and disease states. Although spatiotemporal controls of metal-ion sensors using light have been demonstrated, the lack of penetration depth in tissue and in vivo has limited their application. To overcome this limitation, we herein report the use of high-intensity focused ultrasound (HIFU) to remotely deliver on-demand, spatiotemporally resolved thermal energy to activate the DNAzyme sensors at the targeted region both in vitro and in vivo. A Zn2+-selective DNAzyme probe is inactivated by a protector strand to block the formation of catalytic enzyme structure, which can then be activated by an HIFU-induced increase in the local temperature. With this design, Zn2+-specific fluorescent resonance energy transfer (FRET) imaging has been demonstrated by the new DNAzyme-HIFU probes in both HeLa cells and mice. The current method can be applied to monitor many other metal ions for in vivo imaging and medical diagnosis using metal-specific DNAzymes that have either been obtained or can be selected using in vitro selection.
Asunto(s)
ADN Catalítico , Animales , ADN Catalítico/química , Transferencia de Energía , Células HeLa , Humanos , Iones , Metales/química , RatonesRESUMEN
AIMS: Examine real-world outcomes in patients with type 2 diabetes mellitus (T2DM) initiating injectable therapy as part of the Initiation of New Injectable Treatment Introduced after Antidiabetic Therapy with Oral-only Regimens (INITIATOR) study. MATERIALS AND METHODS: Linked insurance claims and medical record data were collected from 2 large US health insurers (April 1, 2010 to March 31, 2012) of T2DM adults initiating treatment with glargine (GLA) or liraglutide (LIRA). Baseline characteristics were examined and changes in 12-month follow-up outcomes were described for both treatment groups: HbA1c, weight change, hypoglycaemia, persistence, healthcare utilisation and costs. RESULTS: A total of 4490 patients were included (GLA, 2116; LIRA, 2374). At baseline, GLA patients had significantly higher HbA1c vs LIRA patients (9.72% vs 8.19%; P < .001), lower likelihood of having HbA1c < 7% (7.1% vs 23.8%; P < .001), lower bodyweight (100.9 kg vs 110.9 kg, P < .001), higher Charlson Comorbidity Index score (0.88 vs 0.63; P < .001), and higher diabetes-related costs ($3492 vs $2089; P < .001), respectively. During 12-months of follow-up, treatment persistence was 64%, mean HbA1c reduction was -1.24% and weight change was + 1.17 among GLA patients, and was 49%, -0.51% and -2.74 kg, respectively, among LIRA patients. Diabetes-related costs increased significantly from baseline to follow-up for LIRA patients ($2089 vs $3258, P < .001) but not for GLA patients ($3492 vs $3550, P = .890). CONCLUSIONS: There were clinically relevant baseline differences in both groups, suggesting that GLA and LIRA are prescribed for different patient groups, and highlighting that efficacy results from clinical trials do not always translate into real-world practice. Significant increases in healthcare costs were observed in the LIRA group, warranting further cost-effectiveness analysis.
Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina Glargina/uso terapéutico , Liraglutida/uso terapéutico , Adulto , Glucemia/metabolismo , Análisis Costo-Beneficio , Bases de Datos Factuales , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Hemoglobina Glucada/metabolismo , Costos de la Atención en Salud , Servicios de Salud/economía , Servicios de Salud/estadística & datos numéricos , Humanos , Hipoglucemia/inducido químicamente , Hipoglucemiantes/economía , Inyecciones Subcutáneas , Insulina Glargina/economía , Liraglutida/economía , Masculino , Programas Controlados de Atención en Salud , Cumplimiento de la Medicación , Persona de Mediana Edad , Resultado del Tratamiento , Estados UnidosRESUMEN
Three-dimensional measurement arrays are an efficient means of acquiring a distribution of data for patient plan delivery QA. However, the tie between plan integrity and traditional gamma-based analysis of these data are not clear. This study explores the sensitivity of such analysis by creating errors in Helical Tomotherapy delivery and measuring the passing rates with an ArcCHECK cylindrical diode array. Errors were introduced in each of the couch speed, leaf open time, and gantry starting position in increasing magnitude while the resulting gamma passing rates were tabulated. The error size required to degrade the gamma passing rate to 90% or below was on average a 3% change in couch speed, 5° in gantry synchronization, or a 5 ms in leaf closing speed for a 3%/3 mm Van Dyk gamma analysis. This varied with plan type, with prostate plans exhibiting less sensitivity than head and neck plans and with gamma analysis criteria, but in all cases the error magnitudes were large compared to actual machine tolerances. These findings suggest that the sensitivity of ArcCHECK-based gamma analysis to single-mode errors in tomotherapy plans is dependent upon plan and analysis type and at traditional passing thresholds unable to detect small defects in the plan.
Asunto(s)
Rayos gamma , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias de la Próstata/radioterapia , Garantía de la Calidad de Atención de Salud , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/instrumentación , Radioterapia de Intensidad Modulada/normas , Humanos , Masculino , Radiometría , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/métodos , Sensibilidad y EspecificidadRESUMEN
Effectively addressing public health crises like the COVID-19 pandemic requires persuading the mass public to change their behavior in significant ways. Many efforts to encourage behavior change-such as public service announcements, social media posts, and billboards-involve short, persuasive appeals, yet the effectiveness of these messages is unclear. Early in the COVID-19 pandemic, we tested whether short messages could increase intentions to comply with public health guidelines. To identify promising messages, we conducted two pretests (n = 1,596) in which participants rated the persuasiveness of 56 unique messages: 31 based on the persuasion and social influence literatures and 25 drawn from a pool of crowdsourced messages generated by online respondents. The four top-rated messages emphasized: (1) civic responsibility to reciprocate the sacrifices of health care workers, (2) caring for the elderly and vulnerable, (3) a specific, sympathetic victim, and (4) limited health care system capacity. We then conducted three well-powered, pre-registered experiments (total n = 3,719) testing whether these four top-rated messages, and a standard public health message based on language from the CDC, increased intentions to comply with public health guidelines, such as masking in public spaces. In Study 1, we found the four messages and the standard public health message significantly outperformed a null control. In Studies 2 and 3, we compared the effects of persuasive messages to the standard public health message, finding that none consistently out-performed the standard message. This is in line with other research showing minimal persuasive effects of short messages after the very early stages of the pandemic. Across our studies, we found that (1) short messages can increase intentions to comply with public health guidelines, but (2) short messages featuring persuasive techniques from the social science literature did not substantially outperform standard public health messages.
Asunto(s)
COVID-19 , Pandemias , Humanos , Anciano , Pandemias/prevención & control , COVID-19/epidemiología , COVID-19/prevención & control , Salud Pública , Conductas Relacionadas con la Salud , Comunicación PersuasivaRESUMEN
There is widespread concern that rising affective polarization-particularly dislike for outpartisans-exacerbates Americans' anti-democratic attitudes. Accordingly, scholars and practitioners alike have invested great effort in developing depolarization interventions that reduce affective polarization. Critically, however, it remains unclear whether these interventions reduce anti-democratic attitudes, or only change sentiments towards outpartisans. Here we address this question with experimental tests (total n = 8,385) of three previously established depolarization interventions: correcting misperceptions of outpartisans, priming inter-partisan friendships and observing warm cross-partisan interactions between political leaders. While these depolarization interventions reliably reduced affective polarization, we do not find compelling evidence that these interventions reduced support for undemocratic candidates, support for partisan violence or prioritizing partisan ends over democratic means. Thus, future efforts to strengthen pro-democratic attitudes may do better if they target these outcomes directly. More broadly, these findings call into question the previously assumed causal effect of affective polarization on anti-democratic attitudes.
Asunto(s)
Actitud , Política , Humanos , Estados Unidos , ViolenciaRESUMEN
PURPOSE: Total body irradiation (TBI) with megavoltage photon beams has been accepted as an important component of management for a number of hematologic malignancies, generally as part of bone marrow conditioning regimens. The purpose of this paper is to present and discuss the authors' TBI technique, which both simplifies the treatment process and improves the treatment quality. METHODS: An AP/PA TBI treatment technique to produce uniform dose distributions using sequential collimator reductions during each fraction was implemented, and a sample calculation worksheet is presented. Using this methodology, the dosimetric characteristics of both 6 and 18 MV photon beams, including lung dose under cerrobend blocks was investigated. A method of estimating midplane lung doses based on measured entrance and exit doses was proposed, and the estimated results were compared with measurements. RESULTS: Whole body midplane dose uniformity of ±10% was achieved with no more than two collimator-based beam modulations. The proposed model predicted midplane lung doses 5% to 10% higher than the measured doses for 6 and 18 MV beams. The estimated total midplane doses were within ±5% of the prescribed midplane dose on average except for the lungs where the doses were 6% to 10% lower than the prescribed dose on average. CONCLUSIONS: The proposed TBI technique can achieve dose uniformity within ±10%. This technique is easy to implement and does not require complicated dosimetry and/or compensators.
Asunto(s)
Algoritmos , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Irradiación Corporal Total/métodos , Carga Corporal (Radioterapia) , Humanos , Dosificación Radioterapéutica , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
One might expect that VIPs-individuals with wealth, fame, or power-would typically receive excellent care when treated for psychiatric disorders. Often, this is the case, but paradoxically, VIP status may compromise the quality of psychiatric treatment. In this article, we present four case examples, representing disguised amalgamations of actual cases from our experience, demonstrating how VIP patients may sometimes receive suboptimal psychiatric care. These cases show certain similarities; typically, there was no serious doubt about the general nature of the treatment that should be undertaken, but the treatment team was unable to deliver that treatment in the usual manner because of various outside pressures created by the VIP status of the patient and by the patient's entourage. One possible solution to this problem, when feasible, is to assign treatment to a team specifically experienced with VIP patients. A strong and united treatment team, accustomed to the unusual difficulties and pressures often encountered with VIP patients, can be prepared to act promptly, firmly, and unanimously to devise an appropriate treatment plan and then maintain this plan true to its course despite these pressures.
Asunto(s)
Personajes , Trastornos Mentales/rehabilitación , Poder Psicológico , Garantía de la Calidad de Atención de Salud , Clase Social , Adolescente , Adulto , Alcoholismo/psicología , Alcoholismo/rehabilitación , Comorbilidad , Conducta Cooperativa , Trastorno Depresivo Mayor/psicología , Trastorno Depresivo Mayor/rehabilitación , Trastorno Depresivo Resistente al Tratamiento/psicología , Trastorno Depresivo Resistente al Tratamiento/rehabilitación , Disentimientos y Disputas , Femenino , Hospitales Psiquiátricos , Humanos , Comunicación Interdisciplinaria , Masculino , Planificación de Atención al Paciente , Grupo de Atención al Paciente , Cooperación del Paciente , Pacientes Desistentes del Tratamiento/psicología , Esquizofrenia/rehabilitación , Estrés Psicológico/complicaciones , Trastornos Relacionados con Sustancias/psicología , Trastornos Relacionados con Sustancias/rehabilitación , Insuficiencia del Tratamiento , Resultado del TratamientoRESUMEN
The purpose was to study the dosimetric characteristics of the small diameter (≤ 10.0 mm) BrainLAB cones used for stereotactic radiosurgery (SRS) treatments in conjunction with a Varian Trilogy accelerator. Required accuracy and precision in dose delivery during SRS can be achieved only when the geometric and dosimetric characteristics of the small radiation fields is completely understood. Although a number of investigators have published the dosimetric characteristics of SRS cones, to our knowledge, there is no generally accepted value for the relative output factor (ROF) for the 5.0 mm diameter cone. Therefore, we have investigated the dosimetric properties of the small (≤ 10.0 mm) diameter BrainLAB SRS cones used in conjunction with the iPlan TPS and a Trilogy linear accelerator with a SRS beam mode. Percentage depth dose (PDD), off-axis ratios (OAR), and ROF were measured using a SRS diode and verified with Monte Carlo (MC) simulations. The dependence of ROF on detector material response was studied. The dependence of PDD, OAR, and ROF on the alignment of the beam CAX with the detector motion line was also investigated using MC simulations. An agreement of 1% and 1 mm was observed between measurements and MC for PDD and OAR. The calculated ROF for the 5.0 mm diameter cone was 0.692 ± 0.008--in good agreement with the measured value of 0.683 ± 0.007 after the diode response was corrected. Simulations of the misalignment between the beam axis and detector motion axis for angles between 0.5°-1.0° have shown a deviation > 2% in PDD beyond a certain depth. We have also provided a full set of dosimetric data for BrainLAB SRS cones. Monte Carlo calculated ROF values for cones with diameters less than 10.0 mm agrees with measured values to within 1.8%. Care should be exercised when measuring PDD and OAR for small cones. We recommend the use of MC to confirm the measurement under these conditions.
Asunto(s)
Radiometría/instrumentación , Radiocirugia/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Dosificación Radioterapéutica , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The authors interrogate elements of routine medical practice in New York City to argue for reforms of hospital culture through relational trust-building capabilities of community health workers.
Asunto(s)
Agentes Comunitarios de Salud , Confianza , Humanos , Ciudad de Nueva YorkRESUMEN
The purpose of this study was to develop an expertise-based prognostic model for the treatment of complex posttraumatic stress disorder (PTSD) and dissociative identity disorder (DID). We developed a survey in 2 rounds: In the first round we surveyed 42 experienced therapists (22 DID and 20 complex PTSD therapists), and in the second round we surveyed a subset of 22 of the 42 therapists (13 DID and 9 complex PTSD therapists). First, we drew on therapists' knowledge of prognostic factors for stabilization-oriented treatment of complex PTSD and DID. Second, therapists prioritized a list of prognostic factors by estimating the size of each variable's prognostic effect; we clustered these factors according to content and named the clusters. Next, concept mapping methodology and statistical analyses (including principal components analyses) were used to transform individual judgments into weighted group judgments for clusters of items. A prognostic model, based on consensually determined estimates of effect sizes, of 8 clusters containing 51 factors for both complex PTSD and DID was formed. It includes the clusters lack of motivation, lack of healthy relationships, lack of healthy therapeutic relationships, lack of other internal and external resources, serious Axis I comorbidity, serious Axis II comorbidity, poor attachment, and self-destruction. In addition, a set of 5 DID-specific items was constructed. The model is supportive of the current phase-oriented treatment model, emphasizing the strengthening of the therapeutic relationship and the patient's resources in the initial stabilization phase. Further research is needed to test the model's statistical and clinical validity.
Asunto(s)
Trastorno Disociativo de Identidad/terapia , Pautas de la Práctica en Medicina/estadística & datos numéricos , Trastornos por Estrés Postraumático/terapia , Femenino , Humanos , Masculino , Pronóstico , Escalas de Valoración Psiquiátrica , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
By collecting photons scattered out of the therapy beam, scatter imaging creates images of the treated volume. Two phantoms were used to assess the possible application of scatter imaging for markerless tracking of lung tumors during stereotactic body radiation therapy (SBRT) treatment. A scatter-imaging camera was assembled with a CsI flat-panel detector and a 5 mm diameter pinhole collimator. Scatter images were collected during the irradiation of phantoms with megavoltage photons. To assess scatter image quality, spherical phantom lung tumors of 2.1-2.8 cm diameters were placed inside a static, anthropomorphic phantom. To show the efficacy of the technique with a moving target (3 cm diameter), the position of a simulated tumor was tracked in scatter images during sinusoidal motion (15 mm amplitude, 0.25 Hz frequency) in a dynamic lung phantom in open-field, dynamic conformal arc (DCA), and volumetric modulated arc therapy (VMAT) deliveries. Anatomical features are identifiable on static phantom scatter images collected with 10 MU of delivered dose (2.1 cm diameter lung tumor contrast-to-noise ratio of 4.4). The contrast-to-noise ratio increases with tumor size and delivered dose. During dynamic motion, the position of the 3.0 cm diameter lung tumor was identified with a root-mean-square error of 0.8, 1.2, and 2.9 mm for open field (0.3 s frame integration), DCA (0.5 s), and VMAT (0.5 s), respectively. Based on phantom studies, scatter imaging is a potential technique for markerless lung tumor tracking during SBRT without additional imaging dose. Quality scatter images may be collected at low, clinically relevant doses (10 MU). Scatter images are capable of sub-millimeter tracking precision, but modulation decreases accuracy.
Asunto(s)
Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/radioterapia , Imagen Molecular/instrumentación , Fantasmas de Imagen , Radiocirugia/instrumentación , Dispersión de Radiación , Humanos , Radioterapia de Intensidad ModuladaRESUMEN
INTRODUCTION: There is some evidence to suggest that patients with underlying pulmonary fibrosis (PF) have increased risk of adverse respiratory and survival outcomes, when treated with conventional, long-course radiotherapy (RT) for non-small-cell lung cancer (NSCLC). We performed a retrospective analysis to determine the size of these risks. METHODS: Data from 21 patients with PF (cases) were retrospectively analysed for respiratory toxicity and mortality outcomes, and compared with 84 patients without PF (non-cases). Age and mean lung dose were included as covariates in regression analyses. The additional predictive value of other patient, disease and treatment characteristics on radiation pneumonitis (RP) risk and severity was explored. RESULTS: There was a numerical (though not statistically significant) increase in grade ≥ 2 RP among PF cases (OR 2.74, P = 0.074). Cases were significantly more likely to discontinue radical treatment early (OR 6.10, P = 0.015). There was a significant association between increased RP severity and underlying PF (P = 0.039), with RP strongly implicated in the death in 3 of 21 cases (14.3%) compared to 1 non-case (1.2%). Cases experienced increased grade ≥ 2 respiratory toxicity otherwise (OR 4.35, P = 0.020) and poorer median overall survival (0.6 versus 1.7 years, P < 0.001). Two cases, and no non-cases, died during the proposed RT period. None of the analysed patient, disease or treatment factors, was a significant additional predictor of RP risk/severity. CONCLUSION: Patients with PF are at increased risk of treatment discontinuation, respiratory morbidity and mortality, and poor survival following conventional RT for NSCLC. Caution should be exercised when offering high-dose RT to these patients.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/epidemiología , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/radioterapia , Fibrosis Pulmonar/epidemiología , Neumonitis por Radiación/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Australia/epidemiología , Causalidad , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , TiempoRESUMEN
OBJECTIVES: Our objective was to examine the performance characteristics of a bladder stimulation technique for urine collection among infants presenting to the emergency department (ED). METHODS: This prospective cohort study enrolled a convenience sample of infants aged ≤ 90 days requiring urine testing in the ED. Infants were excluded if critically ill, moderately to severely dehydrated, or having significant feeding issues. Bladder stimulation consisted of finger tapping on the lower abdomen with or without lower back massage while holding the child upright. The primary outcome was successful midstream urine collection within 5 minutes of stimulation. Secondary outcomes included sample contamination, bladder stimulation time for successful urine collection, and perceived patient distress on a 100-mm visual analog scale (VAS). RESULTS: We enrolled 151 infants and included 147 in the analysis. Median age was 53 days (interquartile range [IQR] 27-68 days). Midstream urine sample collection using bladder stimulation was successful in 78 infants (53.1%; 95% confidence interval [CI] 45-60.9). Thirty-nine samples (50%) were contaminated. Most contaminated samples (n = 31; 79.5%) were reported as "no significant growth" or "growth of 3 or more organisms". Median bladder stimulation time required for midstream urine collection was 45 seconds (IQR 20-120 seconds). Mean VAS for infant distress was 22 mm (standard deviation 23 mm). CONCLUSIONS: The success rate of this bladder stimulation technique was lower than previously reported. The contamination rate was high, however most contaminated specimens were easily identified and had no clinical impact.
Asunto(s)
Toma de Muestras de Orina , Servicio de Urgencia en Hospital , Humanos , Lactante , Estudios Prospectivos , Vejiga Urinaria , Infecciones UrinariasRESUMEN
PURPOSE: The purpose of this study was to provide guidance on quality management for electronic brachytherapy. MATERIALS AND METHODS: The task group used the risk-assessment approach of Task Group 100 of the American Association of Physicists in Medicine. Because the quality management program for a device is intimately tied to the procedure in which it is used, the task group first designed quality interventions for intracavitary brachytherapy for both commercial electronic brachytherapy units in the setting of accelerated partial-breast irradiation. To demonstrate the methodology to extend an existing risk analysis for a different application, the task group modified the analysis for the case of post-hysterectomy, vaginal cuff irradiation for one of the devices. RESULTS: The analysis illustrated how the TG-100 methodology can lead to interventions to reduce risks and improve quality for each unit and procedure addressed. CONCLUSION: This report provides a model to guide facilities establishing a quality management program for electronic brachytherapy.