Measurement of relative output factors for the 8 and 4 mm collimators of Leksell Gamma Knife Perfexion by film dosimetry

2009 ◽  
Vol 36 (5) ◽  
pp. 1768-1774 ◽  
Author(s):  
Josef Novotny ◽  
Jagdish P. Bhatnagar ◽  
Mubina A. Quader ◽  
Greg Bednarz ◽  
L. Dade Lunsford ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Film Dosimetry ◽  
Output Factors ◽  
Gamma Knife Perfexion

SU-GG-T-450: Measurement of Relative Output Factors for the Leksell Gamma Knife PERFEXION by Film Dosimetry

2008 ◽  
Vol 35 (6Part16) ◽  
pp. 2828-2828 ◽  
Author(s):  
J Novotny ◽  
J Bhatnagar ◽  
M Quader ◽  
M Huq
Keyword(s):  
Gamma Knife ◽  
Film Dosimetry ◽  
Output Factors ◽  
Gamma Knife Perfexion

An Effective Method of Simulation for the Leksell Gamma Knife Perfexion by Rotating Particles in the Phase Space File

2020 ◽  
Vol 65 (1) ◽  
pp. 54-58
Author(s):  
T. Medjadj ◽  
A. Ksenofontov ◽  
A. Dalechina
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Phase Space ◽  
Gamma Knife ◽  
Homogeneous Medium ◽  
Planning System ◽  
Monte Carlo Code ◽  
Output Factors ◽  
Gamma Knife Perfexion ◽  
Conical Form

Purpose: To develop an effective method of Monte Carlo simulation of the GammaKnife Perfexion system by rotating particles in the phase space file (PSF). This method does not require simulating of all 192 sources that are distributed in the conical form of the Perfexion collimator. The simulation was performed only for 5 out of 192 sources for each collimator size. Material and methods: Monte Carlo simulation of dose distribution for previous models of GammaKnife system requires phase space file for only one source, since this phase space is identical for all the 201 sources. The Perfexion model is more complex due to the non-coaxial positions of the sources and the complexity of the collimator system itself. In this work, we present an effective method to simulate the Perfexion model using a phase space file. Penelope Monte Carlo code was used to perform this simulation. In this method, the PSF was obtained for one source in each ring, resulting in five files for each collimator size. PSF for other sources were created by azimuthal redistribution of particles, in the obtained PSF, by rotation around the Z-axis. The phase space files of the same ring were then stored together in a single file. Results: The paper presented MC simulation using the azimuthal redistribution of particles in the phase space file by rotation around the Z-axis. The simulation has been validated comparing the dose profiles and output factors with the data of the algorithm TMR10 planning system Leksell Gamma Plan (LGP) in a homogeneous environment. The acceptance criterion between TMR10 and Monte Carlo calculations for the profiles was based on the gamma index (GI). Index values more than one were not detected in all cases, which indicates a good agreement of results. The differences between the output factors obtained in this work and the TMR10 data for collimators 8 mm and 4 mm are 0.74 and 0.73 %, respectively. Conclusion: In this work successfully implemented an effective method of simulating the Leksell Gamma knife Perfexion system. The presented method does not require modeling for all 192 sources distributed in the conical form of the Perfexion collimator. The simulation was performed for only five sources for each collimator and their files PSF were obtained. These files were used to create the PSF files for other sources by azimuthal redistribution of particles, in these files, by rotation around the Z-axis providing correct calculations of dose distributions in a homogeneous medium for 16, 8 and 4 mm collimators.

Dosimetric comparison of the Leksell Gamma Knife Perfexion and 4C

2008 ◽  
Vol 109 (Supplement) ◽  
pp. 8-14 ◽  
Author(s):  
Josef Novotny ◽  
Jagdish P. Bhatnagar ◽  
Ajay Niranjan ◽  
Mubina A. Quader ◽  
M. Saiful Huq ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Single Shot ◽  
Functional Disorders ◽  
Dose Volume Histograms ◽  
Beam Geometry ◽  
Dose Volume ◽  
Output Factors ◽  
Irradiation Geometry ◽  
The Mean ◽  
Gamma Knife Perfexion

Object The recently introduced Leksell Gamma Knife (LGK) Perfexion is an entirely new system with a different beam geometry compared with the LGK 4C. The new Perfexion system has 192 cobalt-60 sources that are fixed on 8 sectors (each sector has 24 sources). Each sector can be moved independently of the others and can be set to 1 of 5 different positions: 3 positions defining collimator sizes of 4, 8, and 16 mm; an off position (sources are blocked); and a home position. The purpose of this study is to compare the dosimetric characteristics of the GK 4C and the Perfexion models. This comparison is important especially for the treatment of functional disorders when only a single shot with the 4- or 8-mm collimator is used. Methods A 160-mm-diameter spherical polystyrene phantom was used for all measurements and calculations. The irradiation geometry consisted of the placement of a single shot at the center of this phantom. Comparisons were made among different dosimetric parameters obtained from calculations performed using Leksell GammaPlan v. 8.0 and measurements performed using film dosimetry. The dosimetric parameters investigated were dose profiles for all collimators in all 3 stereotactic planes (x, y, and z) including the full width at half maximum and the penumbra for each profile, cumulative dose–volume histograms, the volume encompassed by the 50% isodose surface, the mean doses delivered to a defined matrix volume, and relative output factors for all collimator sizes. Results There was excellent agreement between the dosimetric parameters of GK 4C and Perfexion for the 4- and 8-mm collimators. Conclusions The results of this study suggest that consistent treatments of functional disorders will be delivered using either GK 4C or Perfexion.

GAFChromic film dosimetry with a flatbed color scanner for Leksell Gamma Knife therapy

2004 ◽  
Vol 31 (5) ◽  
pp. 1243-1248 ◽  
Author(s):  
M. Yamauchi ◽  
T. Tominaga ◽  
O. Nakamura ◽  
R. Ueda ◽  
M. Hoshi
Keyword(s):  
Gamma Knife ◽  
Film Dosimetry ◽  
Gafchromic Film ◽  
Color Scanner ◽  
Gamma Knife Therapy

scholarly journals Verification of dose distribution on the gamma knife perfexion radiosurgery using gafchromic EBT3 film: RANDO phantom study

2020 ◽  
Vol 1528 ◽  
pp. 012028
Author(s):  
I N Pranditayana ◽  
A R. Setiadi ◽  
M M Ramadhan ◽  
D Tandian ◽  
S A. Pawiro
Keyword(s):  
Gamma Knife ◽  
Dose Distribution ◽  
Phantom Study ◽  
Gamma Knife Perfexion

scholarly journals Clinical Positioning Accuracy for Multisession Stereotactic Radiotherapy With the Gamma Knife Perfexion

2017 ◽  
Vol 16 (6) ◽  
pp. 893-899
Author(s):  
Wade P. Smith ◽  
Lori A. Young ◽  
Mark H. Phillips ◽  
Michael Cheung ◽  
Lia M. Halasz ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Stereotactic Radiotherapy ◽  
Positioning Accuracy ◽  
Gamma Knife Perfexion

SU-GG-T-513: Patient-Specific Independent GammaPlan Quality Assurance for Gamma Knife Perfexion

2010 ◽  
Vol 37 (6Part23) ◽  
pp. 3305-3305
Author(s):  
M Mamalui-Hunter ◽  
T Zhao ◽  
R Drzymala
Keyword(s):  
Quality Assurance ◽  
Gamma Knife ◽  
Patient Specific ◽  
Gamma Knife Perfexion
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