Search

PurposeThe RefleXion X1 is a novel radiotherapy machine designed for image-guided radiotherapy (IGRT) and biology-guided radiotherapy (BgRT). Its treatment planning system (TPS) generates IMRT and SBRT plans for a 6MV-FFF beam delivered axially via 50 firing positions with the couch advancing every 2.1 mm. The purpose of this work is to report the TPS commissioning results for the first clinical installation of RefleXion™ X1.MethodsCT images of multiple phantoms were imported into the RefleXion TPS to evaluate the accuracy of data transfer, anatomical modeling, plan evaluation, and dose calculation. Comparisons were made between the X1, Eclipse™, and MIM™. Dosimetric parameters for open static fields were evaluated in water and heterogeneous slab phantoms. Representative clinical IMRT and SBRT cases were planned and verified with ion chamber, film, and ArcCHECK@ measurements. The agreement between TPS and measurements for various clinical plans was evaluated using Gamma analysis with a criterion of 3%/2 mm for ArcCHECK@ and film. End-to-end (E2E) testing was performed using anthropomorphic head and lung phantoms.ResultsThe average difference between the TPS-reported and known HU values was -1.4 ± 6.0 HU. For static fields, the agreements between the TPS-calculated and measured PDD10 , crossline profiles, and inline profiles (FWHM) were within 1.5%, 1.3%, and 0.5 mm, respectively. Measured output factors agreed with the TPS within 1.3%. Measured and calculated dose for static fields in heterogeneous phantoms agreed within 2.5%. The ArcCHECK@ mean absolute Gamma passing rate was 96.4% ± 3.4% for TG 119 and TG 244 plans and 97.8% ± 3.6% for the 21 clinical plans. E2E film analysis showed 0.8 mm total targeting error for isocentric and 1.1 mm for off-axis treatments.ConclusionsThe TPS commissioning results of the RefleXion X1 TPS were within the tolerances specified by AAPM TG 53, MPPG 5.a, TG 119, and TG 148. A subset of the commissioning tests has been identified as baseline data for an ongoing QA program.

We examined whether baseline self-reported physical activity is associated with the efficacy of cognitive behavioral therapy for insomnia (CBT-I) in older veterans. Community-dwelling veterans aged 60 years and older with insomnia received CBT-I in a randomized controlled trial. Participants who received active treatment were divided into low and high physical activity based on self-report. Sleep outcomes were measured by sleep diary, questionnaire and wrist actigraphy; collected at baseline, post-treatment, 6-month and 12-month follow-up. Mixed-effects models compared differences between physical activity groups in change in sleep outcome from baseline to each follow-up, and equivalence tests examined if physical activity groups were clinically equal. There were no significant differences in sleep outcomes between physical activity groups. Equivalence tests suggested possible equality in physical activity groups for five of seven sleep outcomes. Efficacy of CBT-I in older veterans was not associated with self-reported physical activity at baseline. Older adults with insomnia who report low levels of physical activity can benefit from CBT-I.

This paper examines the vaccine diplomacy efforts of China, Russia, and the EU in the Western Balkans during the COVID-19 pandemic. Building on Schmitt’s (2018) framework, it explores how recipient countries selectively chose evidence in support of political myth-building. Quantitatively, the EU was the largest vaccine donor to the region during the pandemic, yet survey data reveal no significant improvement in public attitudes toward the EU. To explain this paradox, the paper explores the reception in the Western Balkans, particularly in Serbia, arguing that the selective evidence processing and response played a critical role in shaping public perceptions. The selective reception of external narratives hindered the EU’s ability to shift public sentiment, despite its substantial vaccine contributions. Furthermore, the paper highlights the well-crafted strategic narratives and the follow-up interventions by China and Russia, which capitalized on local political myths to reinforce their influence, effectively countering the EU’s efforts. [ABSTRACT FROM AUTHOR]