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Title: SU-E-T-605: A New Design for a Rotating Gamma Knife. Monte Carlo Simulation

Abstract

Purpose: to determine the characteristics of the 60Co beam emerging from a new design of a rotating Gamma Knife system and to calculate 3D dose distributions at the isocenter for different source configurations and collimator openings. Methods: We employed the BEAM-Monte Carlo code to realistically model the geometry design, including 30 60Co source capsules, two circular primary collimators (diameter of 6.6mm and 6.1mm) and four different changeable collimators. The shielding of the head design was also simulated. The sources (2.8mm diameter) are distributed in six groups in the spherical geometry. Each source is individually collimated to obtained four different circular fields at the isocenter (3mm, 3.5mm, 6mm and 8mm).The phase-space particles reaching the scoring plane below the primary collimation assembly were recorded and the BEAMDP code was used to determine the fluence and energy spectra of the particles emerging from each source-collimator configuration. The dose distributions at the isocenter plane (397.6mm from the source) were calculated in a spherical component module for the circular field sizes studied. Results: The energy spectra below the head assembly and primary collimators have been obtained, which exhibited the typical 60Co peaks and a small low-energy tail due to scattered photons (from about 200keV tomore » 1MeV). The scattered component of the spectra represents about 8 % of the total number of photons reaching the scoring plane. The radial photon fluence does not vary significantly inside the collimator openings. The spectra of particles from different source groups are compared. Conclusion: The 60Co beam emerging from each source configuration was characterized, which can be used to establish a generic source model for all the sources for fast MC dose calculation. Further investigations are needed to determine the dose variations as a result of partial switching on/off different groups of sources for advanced Gamma Knife SRS/SBRT planning.« less

Authors:
 [1]; ; ;  [2]
  1. Universidade de Lisboa, Lisboa (Portugal)
  2. Fox Chase Cancer Center, Philadelphia, PA (United States)
Publication Date:
OSTI Identifier:
22369721
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 41; Journal Issue: 6; Other Information: (c) 2014 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
07 ISOTOPES AND RADIATION SOURCES; COLLIMATORS; COMPUTERIZED SIMULATION; MONTE CARLO METHOD; PHASE SPACE; PLANNING; RADIATION DOSE DISTRIBUTIONS; SHIELDING

Citation Formats

Mora, G, Chibani, O, Li, J, and Ma, C. SU-E-T-605: A New Design for a Rotating Gamma Knife. Monte Carlo Simulation. United States: N. p., 2014. Web. doi:10.1118/1.4888941.
Mora, G, Chibani, O, Li, J, & Ma, C. SU-E-T-605: A New Design for a Rotating Gamma Knife. Monte Carlo Simulation. United States. https://doi.org/10.1118/1.4888941
Mora, G, Chibani, O, Li, J, and Ma, C. 2014. "SU-E-T-605: A New Design for a Rotating Gamma Knife. Monte Carlo Simulation". United States. https://doi.org/10.1118/1.4888941.
@article{osti_22369721,
title = {SU-E-T-605: A New Design for a Rotating Gamma Knife. Monte Carlo Simulation},
author = {Mora, G and Chibani, O and Li, J and Ma, C},
abstractNote = {Purpose: to determine the characteristics of the 60Co beam emerging from a new design of a rotating Gamma Knife system and to calculate 3D dose distributions at the isocenter for different source configurations and collimator openings. Methods: We employed the BEAM-Monte Carlo code to realistically model the geometry design, including 30 60Co source capsules, two circular primary collimators (diameter of 6.6mm and 6.1mm) and four different changeable collimators. The shielding of the head design was also simulated. The sources (2.8mm diameter) are distributed in six groups in the spherical geometry. Each source is individually collimated to obtained four different circular fields at the isocenter (3mm, 3.5mm, 6mm and 8mm).The phase-space particles reaching the scoring plane below the primary collimation assembly were recorded and the BEAMDP code was used to determine the fluence and energy spectra of the particles emerging from each source-collimator configuration. The dose distributions at the isocenter plane (397.6mm from the source) were calculated in a spherical component module for the circular field sizes studied. Results: The energy spectra below the head assembly and primary collimators have been obtained, which exhibited the typical 60Co peaks and a small low-energy tail due to scattered photons (from about 200keV to 1MeV). The scattered component of the spectra represents about 8 % of the total number of photons reaching the scoring plane. The radial photon fluence does not vary significantly inside the collimator openings. The spectra of particles from different source groups are compared. Conclusion: The 60Co beam emerging from each source configuration was characterized, which can be used to establish a generic source model for all the sources for fast MC dose calculation. Further investigations are needed to determine the dose variations as a result of partial switching on/off different groups of sources for advanced Gamma Knife SRS/SBRT planning.},
doi = {10.1118/1.4888941},
url = {https://www.osti.gov/biblio/22369721}, journal = {Medical Physics},
issn = {0094-2405},
number = 6,
volume = 41,
place = {United States},
year = {Sun Jun 01 00:00:00 EDT 2014},
month = {Sun Jun 01 00:00:00 EDT 2014}
}