A Case for Cross-Border Governance? A Comparative Trend Assessment of COVID-19 Transmission, Vaccination, and Outcomes Among 35 Nations in Europe Across 18 months.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) spread globally, including across Europe, resulting in different morbidity and mortality outcomes. The aim of this study was to explore the progression of the COVID-19 pandemic over 18 mo in relation to the effect of COVID-19 vaccination at a population level across 35 nations in Europe, while evaluating the data for cross-border epidemiological trends to identify any pertinent lessons that can be implemented in the future. METHODS: Epidemiological data were obtained from European Centre for Disease Prevention and Control and Our World in Data databases while Ministry of Health websites of each respective country and local newspapers were used for COVID-19-related vaccination strategies. Case, mortality, and vaccination incidence comparative analyses were made across neighboring countries. RESULTS: Similar morbidity and mortality outcomes were evident across neighboring countries over 18 mo, with a bidirectional relationship evident between cumulative fully vaccinated population and case fatality rates. CONCLUSION: Countries' COVID-19 outcome is related on national mitigative measures, vaccination rollouts, and neighboring countries' actions and COVID-19 situations. Mass population vaccination appeared to be effective in reducing COVID-19 case severity and mortality rates. Vaccination equity and pan-European commitment for cross-border governance appear to be the way forward to ensure populations' return to "normality."

Influence of intra- and interfraction motion on planning target volume margin in liver stereotactic body radiation therapy using breath hold.

PURPOSE: This study aimed to investigate intra- and interfraction motion during liver stereotactic body radiation therapy for the purpose of planning target volume (PTV) margin estimation, comparing deep inspiration breath hold (DIBH) and deep expiration breath hold (DEBH). METHODS AND MATERIALS: Pre- and posttreatment kV cone beam computed tomography (CT) images were acquired for patients with liver cancer who were treated using stereotactic body radiation therapy with DIBH or DEBH. A total of 188 images were analyzed from 18 patients. Positioning errors were determined based on a comparison with planning CT images and matching to the liver. Treatment did not proceed until errors were ≤3 mm. Standard deviations of random and systematic errors resulting from this image matching process were used to calculate PTV margin estimates. RESULTS: DIBH errors are generally larger than DEBH errors, especially in the anterior-posterior and superior-inferior directions. Posttreatment errors tend to be larger than pretreatment errors, especially for DIBH. Standard deviations of random errors are larger than those of systematic errors. Considering both pre- and posttreatment cone beam CT images, PTV margins for DIBH and DEBH are estimated as anterior-posterior, superior-inferior, right-left = (5.7, 6.3, 3.0) mm and (3.1, 3.4, 2.8) mm, respectively. CONCLUSIONS: This study suggests that DEBH results in more reproducible target positioning, which could in turn justify the use of smaller PTV margins.