Dose calculations with a collapsed cone algorithm implemented in a clinical treatment planning system have been studied. The algorithm has been evaluated in homogeneous as well as in heterogeneous media, and the results have been compared to measurements and Monte Carlo simulations. Commonly encountered clinical beam configurations as well as more complex geometries have been pursued to test the limitations of the model. The results show that the accuracy level reached allows for clinical use. Some situations, e.g., large wedge beams and dose calculations in the build up region, not specific to the collapsed cone model, show deviations (outside +/- 3%) compared to measurements.
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http://dx.doi.org/10.1120/jacmp.v3i2.2579 | DOI Listing |
Med Phys
January 2025
Department of Radiation Medicine and Applied Sciences, University of California at San Diego, La Jolla, California, USA.
Background: Proton pencil beam scanning (PBS) treatment planning for head and neck (H&N) cancers is a time-consuming and experience-demanding task where a large number of potentially conflicting planning objectives are involved. Deep reinforcement learning (DRL) has recently been introduced to the planning processes of intensity-modulated radiation therapy (IMRT) and brachytherapy for prostate, lung, and cervical cancers. However, existing DRL planning models are built upon the Q-learning framework and rely on weighted linear combinations of clinical metrics for reward calculation.
View Article and Find Full Text PDFJ Med Radiat Sci
January 2025
Radiation Oncology Princess Alexandra Hospital Ipswich Road Brisbane, Brisbane, Queensland, Australia.
Introduction: Image guided-radiation therapy (IGRT) protocols are adopted to ensure the accurate dose delivery of patient treatments. This is especially important in hypofractionated treatments, such as stereotactic body radiation therapy (SBRT), as high doses of radiation are delivered, and incorrect treatment can have a significant impact on tumour control and toxicity. This study aimed to establish mean treatment times from the localisation image to the post-treatment image in SBRT liver, lung and spine patients that utilised Elekta Intrafraction Imaging (IFI).
View Article and Find Full Text PDFVopr Pitan
January 2025
Federal Research Centre of Nutrition, Biotechnology and Food Safety, 109240, Moscow, Russian Federation.
The main molecular mechanisms of the protective effect of minor bioactive compounds (BAC) of food, including rutin and hesperidin, along with antiradical and antioxidant activity, include their interaction with transcription factors modulating the functional state of the organism defense systems, one of which is the system of xenobiotic metabolizing enzymes. However, the data on their combined action are limited. of the research was to study the effect of rutin and hesperidin on the activity and gene expression of cytochrome P450 isoforms 1A and 3A (CYP1A1, CYP1A2, CYP3A) in rat liver at their separate and combined intake.
View Article and Find Full Text PDFPhys Imaging Radiat Oncol
January 2025
Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
The McNamara (MCN) and Wedenberg (WED) RBE weighted dose (D), dose and dose-weighted average LET (LET) were calculated in twenty brain cancer patients. A linear approximation was made for each RBE model to give best agreement to clinically relevant dosimetric parameters. Additional evaluations were done on twenty head and neck and twenty breast cancer patients.
View Article and Find Full Text PDFSci Prog
January 2025
Critical Care Medicine, Fortis Hospital Bannerghatta road, Bengaluru, Karnataka, India.
Objective: To study the impact of kinetic glomerular filtration rate (kGFR) on clinical decision making and its implications on drug dosing compared to that of estimated GFR (eGFR) using chronic kidney disease epidemiology collaboration (CKD-EPI) equation in critically ill patients with acute kidney injury (AKI) admitted in a tertiary level intensive care unit (ICU).
Methods: Cross-sectional, prospective, observational study design. All patients admitted to Medical ICU, Fortis Hospital, Bangalore with AKI defined as per AKI network (AKIN) criteria.
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