Purpose: To present a reference Monte Carlo (MC) beam model developed in GATE/Geant4 for the MedAustron fixed beam line. The proposed model includes an absolute dose calibration in Dose-Area-Product (DAP) and it has been validated within clinical tolerances for non-isocentric treatments as routinely performed at MedAustron.
Material And Methods: The proton beam model was parametrized at the nozzle entrance considering optic and energy properties of the pencil beam. The calibration in terms of absorbed dose to water was performed exploiting the relationship between number of particles and DAP by mean of a recent formalism. Typical longitudinal dose distribution parameters (range, distal penumbra and modulation) and transverse dose distribution parameters (spot sizes, field sizes and lateral penumbra) were evaluated. The model was validated in water, considering regular-shaped dose distribution as well as clinical plans delivered in non-isocentric conditions.
Results: Simulated parameters agree with measurements within the clinical requirements at different air gaps. The agreement of distal and longitudinal dose distribution parameters is mostly better than 1 mm. The dose difference in reference conditions and for 3D dose delivery in water is within 0.5% and 1.2%, respectively. Clinical plans were reproduced within 3%.
Conclusion: A full nozzle beam model for active scanning proton pencil beam is described using GATE/Geant4. Absolute dose calibration based on DAP formalism was implemented. The beam model is fully validated in water over a wide range of clinical scenarios and will be inserted as a reference tool for research and for independent dose calculation in the clinical routine.
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http://dx.doi.org/10.1016/j.ejmp.2020.02.006 | DOI Listing |
J Magn Reson Imaging
January 2025
High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.
Background: Pancreatic damage is a common digestive system disease with no specific drugs. Static magnetic field (SMF), the key component of magnetic resonance imaging (MRI), has demonstrated prominent effects in various disease models.
Purpose: To study the effects of 0.
BMC Oral Health
January 2025
Department of Stomatology, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde, Foshan), Foshan, 528308, Guangdong, China.
Background: A comprehensive analysis of the occlusal plane (OP) inclination in predicting anteroposterior mandibular position (APMP) changes is still lacking. This study aimed to analyse the relationships between inclinations of different OPs and APMP metrics and explore the feasibility of OP inclination in predicting changes in APMP.
Methods: Overall, 115 three-dimensional (3D) models were reconstructed using deep learning-based cone-beam computed tomography (CBCT) segmentation, and their accuracy in supporting cusps was compared with that of intraoral scanning models.
Stargardt disease is a currently untreatable, inherited neurodegenerative disease that leads to macular degeneration and blindness due to loss-of-function mutations in the ABCA4 gene. We have designed a dual adeno-associated viral vector encoding a split-intein adenine base editor to correct the most common mutation in ABCA4 (c.5882G>A, p.
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January 2025
Department of Radiation Oncology, Masaryk Memorial Cancer Institute, Zluty kopec 7, Brno, 656 53, Czech Republic.
Accelerated partial breast irradiation (APBI) represents a valid option for adjuvant therapy of selected early breast cancer (BC). This single-institution prospective randomized study compares the health-related quality of life (HRQoL) between women treated with the highly conformal-external beam APBI technique and those with the more commonly used moderately hypofractionated whole breast irradiation (hypo-WBI). Eligible patients were women over 50 years with early BC (G1/2 DCIS ≤ 25 mm or G1/2 invasive non-lobular luminal-like HER2 negative carcinoma ≤ 20 mm) after breast-conserving surgery with negative margins.
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January 2025
Department of Electrical Engineering, Faculty of Science and Technology, University Al Azhar Indonesia, Jakarta, Indonesia.
Curvature of a dielectric waveguide always leads to attenuation of the mode power as it propagates through the curved region. In single mode guides, bending loss becomes significant as the radius of curvature reduces and is strongly dependent on the confinement of the guided mode, so that weakly guiding waveguides can tolerate only large radii of curvature. In this paper we verify our new theoretical version on power loss prediction of S-bend optical waveguides by using analytical theory based on integration of absorption coefficient and compare it to the experimental measurement of such waveguide bends.
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