Purpose: Study of behavior and influence of a multileaf collimator (MLC) on dose calculation, verification, and portal energy spectra in the case of intensity-modulated fields obtained with a step-and-shoot or a dynamic technique.
Methods: The 80-leaf MLC for the Varian Clinac 2300 C/D was implemented in a previously developed Monte Carlo (MC) based multiple source model (MSM) for a 6 MV photon beam. Using this model and the MC program GEANT, dose distributions, energy fluence maps and energy spectra at different portal planes were calculated for three different MLC applications.
Results: The comparison of MC-calculated dose distributions in the phantom and portal plane, with those measured with films showed an agreement within 3% and 1.5 mm for all cases studied. The deviations mainly occur in the extremes of the intensity modulation. The MC method allows to investigate, among other aspects, dose components, energy fluence maps, tongue-and-groove effects and energy spectra at portal planes.
Conclusion: The MSM together with the implementation of the MLC is appropriate for a number of investigations in intensity-modulated radiation therapy (IMRT).
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0939-3889(15)70508-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Capillary Wave-Assisted Colloidal Assembly.
Langmuir
January 2025
Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
The self-assembly of nanoparticle colloids into large-area monolayers with long-range order is a grand challenge in nanotechnology. Using acoustic energy, i.e.
View Article and Find Full Text PDFRaman spectra of pyromorphite, vanadinite and mimetite at high pressures and high temperatures.
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Key Laboratory of High-temperature and High-pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081 Guizhou, China. Electronic address:
High-pressure and high-temperature Raman spectra of natural pyromorphite, vanadinite and mimetite were measured up to 11 GPa and 973 K, respectively. No phase transition was observed within the temperature and pressure ranges in this study. Raman modes for pyromorphite, vanadinite and mimetite vary with temperature or pressure linearly.
View Article and Find Full Text PDFTime-resolved vibronic spectra with nuclear-electronic orbital time-dependent configuration interaction.
J Chem Phys
January 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Time-resolved spectroscopy is an important tool for probing photochemically induced nonequilibrium dynamics and energy transfer. Herein, a method is developed for the ab initio simulation of vibronic spectra and dynamical processes. This framework utilizes the recently developed nuclear-electronic orbital time-dependent configuration interaction (NEO-TDCI) approach, which treats all electrons and specified nuclei quantum mechanically on the same footing.
View Article and Find Full Text PDFPutting Charge Transfer Degree as a Bridge Connecting Surface-Enhanced Raman Spectroscopy and Photocatalysis.
Angew Chem Int Ed Engl
January 2025
Jilin University, State Key Laboratory of Supramolecular Structure and Materials, 2699 Qianjin Street, 130012, Changchun, CHINA.
To date, few systematic approach has been established for predicting catalytic performance by analyzing the spectral information of molecules adsorbed on photocatalyst surfaces. Effective charge transfer (CT) between the semiconductor photocatalysts and surface-absorbed molecules is essential for enhancing catalytic activity and optimizing light energy utilization. This study aimed to validate the surface-enhanced Raman spectroscopy (SERS) based on the CT enhancement mechanism in investigating the CT process during semiconductor photocatalytic C-C coupling model reactions.
View Article and Find Full Text PDFPredicting Perovskite Photovoltaics Performance.
ACS Appl Mater Interfaces
January 2025
Department of Physics and Astronomy & Wright Center for Photovoltaic Innovation and Commercialization, The University of Toledo, Toledo, Ohio 43606, United States.
Wide band gap FACsPb(IBr) perovskite photovoltaic (PV) devices are measured by spectroscopic ellipsometry in the through-the-glass configuration and analyzed to determine the complex optical property spectra of the perovskite absorber as well as the structural properties of all constituent layers. This information is used to simulate external quantum efficiency (EQE) spectra, to calculate PV device performance parameters such as short circuit current density, open circuit voltage, fill factor, and power conversion efficiency, and to develop strategies for increasing the accuracy of predictions. Simulations and calculations tend to overestimate PV device performance parameters, undermining the accuracy and usefulness of those simulations.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!