Purpose: Measurement of beam alignment, including an isocenter, is a fundamental part of commissioning and quality assurance for a medical linear accelerator (linac). An alignment shift is caused by the focal spot displacement from the beam axis. In this study, we present a procedure for the analysis of the focal spot positions in the radiation alignment using a newly developed quality control tool (QCT) device and analysis software.
Methods: The device has the function to perform the light/radiation field coincidence test, and the isocenter test at the same time. First, the light/radiation field was evaluated by using cross-slits on the surface of the QCT device. Second, the focal spot positions of beam alignment were measured using QCT, and the acquired images were collectively analyzed using the developed analysis software. Finally, measurements of focal spot positions with different energies were made using the accelerators at the 2 facilities.
Results: The focal spot position was changed with a gantry angle. The focal spot displacement was 0.15-1.37 mm. With the validation of 2 accelerators at 2 facilities, the displacement of the focal spot position could be measured using the QCT phantom.
Conclusion: The focal spot position measurement using the QCT test captured the change in the beam alignment between the beam axes without being affected by the jaw collimator. This study suggested that focal spot position measurement using a QCT device is useful for evaluating beam alignment at linac.
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http://dx.doi.org/10.6009/jjrt.25-1472 | DOI Listing |
J Hazard Mater
December 2024
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Institute of Analytical Food Safety, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address:
Antibiotic resistance genes (ARGs) are markers of drug-resistant pathogens, monitoring them contributes to prevent resistance to drugs. The detection methods for ARGs including PCR and isothermal amplification are sensitive and selective. However, it may take several hours or cannot be used on spot.
View Article and Find Full Text PDFHeliyon
November 2024
Department of Industrial & Production Engineering, Rajshahi University of Engineering & Technology (RUET), Rajshahi- 6204, Bangladesh.
To balance the convergence speed and solution diversity and enhance optimization performance when addressing large-scale optimization problems, this research study presents an improved ant colony optimization (ICMPACO) technique. Its foundations include the co-evolution mechanism, the multi-population strategy, the pheromone diffusion mechanism, and the pheromone updating method. The suggested ICMPACO approach separates the ant population into elite and common categories and breaks the optimization problem into several sub-problems to boost the convergence rate and prevent slipping into the local optimum value.
View Article and Find Full Text PDFOpen Vet J
November 2024
Department of Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine, Matrouh University, Matrouh, Egypt.
Background: Highly pathogenic avian influenza (HPAI) (H5N1) has been endemic in Egypt for almost two decades, profoundly impacting both the poultry industry and public health. Egypt stands as a prominent epicenter for HPAI H5N1 outbreaks in Africa, marked by the highest number of positive human cases. Despite continuous governmental efforts, prior research underscored the inadequacy of strategies in controlling the virus spread.
View Article and Find Full Text PDFInt J Behav Nutr Phys Act
December 2024
The George Institute for Global Health, University of New South Wales, Level 18, International Towers 3, 300 Barangaroo Ave, Sydney, NSW, 2000, Australia.
Background: Online grocery shopping is a growing source of food purchases in many countries. We investigated the effect of nudging consumers towards purchases of lower sodium products using a web browser extension.
Methods: This trial was conducted among individuals with hypertension who shopped for their groceries online in Australia.
BMC Infect Dis
December 2024
Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu Province, PR China.
Background: This study aimed to evaluate the diagnostic performance of ESAT6-CFP10 (EC) skin test in healthy population and determine the factors influencing the booster effect.
Methods: We conducted a randomized, double-blind, parallel controlled trial in healthy population. The experiment was divided into two stages.
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