Conectar
by Dong Min Jung, Yong Jae Kwon, Yong Wan Cho, Jong Geol Baek, Dong Jae Jang, Yongdo Yun, Seok-Ho Lee, Gahee Son, Hyunjong Yoo, Min Cheol Han, Jin Sung Kim
Volumetric modulated arc therapy (VMAT) for lung cancer involves complex multileaf collimator (MLC) motion, which increases sensitivity to interplay effects with tumour motion. Current dynamic conformal arc methods address this issue but may limit the achievable dose distribution optimisation compared with standard VMAT. This study examined the clinical utility of a VMAT technique with monitor unit limits (VMATliMU) to mimic conformal arc delivery and reduce interplay effects while maintaining plan quality. VMATliMU was implemented by applying monitor unit limitations during VMAT reoptimisation to minimise MLC encroachment into target volumes. Using mesh-type reference computational phantom CT images, treatment plans were generated for a simulated stage I lung cancer case prescribed to 45 Gy in three fractions. VMATliMU, conventional VMAT, VMAT with leaf speed limitations, dynamic conformal arc therapy, and constant dynamic conformal arc therapy were compared. Plans were optimised for multiple isodose line prescriptions (50%, 60%, 70%, 80%, and 90%) to investigate the impact of dose distribution. Evaluation parameters included MLC positional accuracy using area difference ratios, dosimetric indices, gradient metrics, and organ-at-risk doses. VMATliMU prevented MLC encroachment into the internal target volume across 60%–90% isodose lines, showing superior MLC accuracy compared with other methods. At the challenging 50% isodose line, VMATliMU had 4.5 times less intrusion than VMAT with leaf speed limits. VMAT plans had better dosimetric indices than dynamic conformal arc plans. VMATliMU reduced monitor units by 5.1%–19.2% across prescriptions. All plans met the clinical dose constraints, with the aortic arch below tolerance and acceptable lung doses. VMATliMU combines VMAT’s dosimetric benefits with the dynamic conformal arcs’s simplicity, minimising MLC encroachment while maintaining plan quality. Reduced monitor units lower low-dose exposure, treatment time, and interplay effects. VMATliMU is usable in existing planners with monitor unit limits, offering a practical solution for lung stereotactic body radiation therapy.
by Jasmine C. Mah, Olga Theou, Mario Ulises Perez-Zepeda, Jodie L. Penwarden, Judith Godin, Kenneth Rockwood, Melissa K. Andrew
BackgroundThe construct of social vulnerability attempts to understand social circumstances not merely as a descriptor, but as a predictor of adverse health events. It can be measured by aggregating social deficits in a social vulnerability index (SVI). We describe a standard procedure for constructing a multi-level SVI using two working examples.
MethodsFirst, we describe a six-step approach to constructing a SVI. Then, we conducted a secondary analysis of a clinical dataset (Canadian Immunization Research Network’s Serious Outcomes Surveillance Network (SOS)) and a population-based dataset (Canadian Longitudinal Study on Aging (CLSA)). In both datasets, we construct SVIs, use descriptive statistics to report distributions by age and sex, and perform a multivariable linear regression of social vulnerability on frailty.
ResultsProcedures for drafting a list of candidate social items, selecting deficits for inclusion, and screening deficits to meet inclusion criteria were applied to yield a 18-deficit SVI for the SOS and 74-deficit SVI for the CLSA. Deficits in each SVI were re-scored between 0 and 1, where 1 indicates the greater risk. Finally, the sum of all deficits is calculated into an index. In the SOS, SVI was associated with age only for females and was weakly associated with frailty (r = 0.26, p Conclusion
We present a standard method of constructing a SVI by incorporating factors from multiple social domains and levels in a social-ecological model. This SVI can be used to improve our understanding of social vulnerability and its impacts on the health of communities and individuals.
by Daeyun Seo, Seongsoo Lim, Beomkwan Namgoong, Heesung Uhm, Hyeajeong Hong, Nanju Lee, Isong Kim, Seunghun Heo, Ji Hwan Kang, Cheyoun Kim, Hayoung Shin, Jiwoong Her, Min Su Kim
ObjectiveLiver compression (LC) has been proposed to predict fluid responsiveness in human pediatric patients. Because the evaluation of fluid responsiveness through LC depends on the mechanism of increased intra-abdominal pressure (IAP), understanding the impact of LC on IAP, cardiac output (CO), and respiratory parameters is essential. Thus, this study aimed to investigate the effects of LC on these parameters.
MethodsThe present study used six healthy beagles. All dogs were anesthetized with isoflurane and allowed to breathe spontaneously in dorsal recumbency. After instrumentation, LC was performed at four different pressures in a sequential, non-randomized manner: (1) 10 mmHg, approximately half of the minimum value within the range; (2) 22 mmHg, a commonly used pressure within the range; (3) 44 mmHg, twice the pressure of the minimum value within the range; and (4) 60 mmHg, twice the pressure of the maximum value within the range. At each pressure, CO via transthoracic echocardiography, IAP, and cardiorespiratory parameters were measured before, during, and after LC.
ResultsOverall, our results showed that the IAP was significantly increased at all pressures during LC (P Conclusions
This is the first study to evaluate the effects of LC on IAP, CO, and respiratory parameters in healthy, anesthetized, and spontaneously breathing dogs. Our findings indicate that applying LC with a commonly used pressure may have a low risk of inducing intra-abdominal hypertension and related complications. Further studies are required to explore the use of LC in various clinical settings.
by Minkwan Kim, Seok-Jae Heo, Moon-Hyun Kim, Je-Wook Park, SungA Bae, Ji Woong Roh, Oh-Hyun Lee, Yongcheol Kim, Eui Im, In Hyun Jung, Deok-Kyu Cho
Sodium-glucose cotransporter 2 inhibitors (SGLT2i), have shown benefits in patient with heart failure (HF), however, adherence remains a significant issue: with only 60% of patients continuing usage beyond a year. This study aims to identify patients at risk of discontinuing SGLT2i and promote its judicious use to reduce hospitalizations and improve cardiovascular outcomes. Using the Korean National Health Insurance Service database, patients diagnosed with HF and diabetes mellitus (n = 1,665,565) between 2013 and 2018 were identified. Among them, 55,694 participants prescribed SGLT2i were enrolled. The primary endpoint included 1) all-cause mortality and 2) SGLT2i-related hospitalization, encompassing incidents such as ketoacidosis, acute kidney injury, urinary tract infections, fall-related fractures, and other unplanned hospitalizations. During the follow-up period (median: 2.3 years; range: 1.2–3.6 years), 8,463 participants reached the primary endpoint (25.5 for all-cause death and 39.4 for SGLT2i-related hospitalizations per 1,000 person-years). Independent risk factors for the primary endpoint in multivariate Cox regression and propensity-score matching analyses included age of ≥ 70 years, body mass index (BMI) 2, body weight pp
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