WE-E-BRA-06: Imaging Linear Accelerator Startup Using a High-Speed Scintillation Based Electronic Portal Imaging Device (Hi-EPID)

2007 ◽  
Vol 34 (6Part21) ◽  
pp. 2612-2612
Author(s):  
M Ranade ◽  
B Lynch ◽  
J Li ◽  
S Kim ◽  
J Dempsey
Keyword(s):  
Linear Accelerator ◽  
High Speed ◽  
Electronic Portal Imaging Device ◽  
Imaging Device ◽  
Portal Imaging ◽  
Electronic Portal Imaging

Quality assurance of linear accelerator: a comprehensive system using electronic portal imaging device

2018 ◽  
Vol 18 (02) ◽  
pp. 138-149
Author(s):  
P. Niyas ◽  
K. K. Abdullah ◽  
M. P. Noufal ◽  
R. Vysakh
Keyword(s):  
Quality Assurance ◽  
Linear Accelerator ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Array Detector ◽  
Electronic Portal Imaging Device ◽  
Imaging Device ◽  
Portal Imaging ◽  
Electronic Portal Imaging

AbstractAimThe Electronic Portal Imaging Device (EPID), primarily used for patient setup during radiotherapy sessions is also used for dosimetric measurements. In the present study, the feasibility of EPID in both machine and patient-specific quality assurance (QA) are investigated. We have developed a comprehensive software tool for effective utilisation of EPID in our institutional QA protocol.Materials and methodsPortal Vision aS1000, amorphous silicon portal detector attached to Clinac iX—Linear Accelerator (LINAC) was used to measure daily profile and output constancy, various Multi-Leaf Collimator (MLC) checks and patient plan verification. Different QA plans were generated with the help of Eclipse Treatment Planning System (TPS) and MLC shaper software. The indigenously developed MATLAB programs were used for image analysis. Flatness, symmetry, output constancy, Field Width at Half Maximum (FWHM) and fluence comparison were studied from images obtained from TPS and EPID dosimetry.ResultsThe 3 years institutional data of profile constancy and patient-specific QA measured using EPID were found within the acceptable limits. The daily output of photon beam correlated with the output obtained through solid phantom measurements. The Pearson correlation coefficients are 0.941 (p = 0.0001), 0.888 (p = 0.0188) and 0.917 (p = 0.0007) for the years of 2014, 2015 and 2016, respectively. The accuracy of MLC for shaping complex treatment fields was studied in terms of FWHM at different portions of various fields, showed good agreement between TPS-generated and EPID-measured MLC positions. The comparison of selected patient plans in EPID with an independent 2D array detector system showed statistically significant correlation between these two systems. Percentage difference between TPS computed and EPID measured fluence maps calculated for number of patients using MATLAB code also exhibited the validity of those plans for treatment.

A high-speed scintillation-based electronic portal imaging device to quantitatively characterize IMRT delivery

2005 ◽  
Vol 33 (1) ◽  
pp. 106-110 ◽  
Author(s):  
Manisha K. Ranade ◽  
Bart D. Lynch ◽  
Jonathan G. Li ◽  
James F. Dempsey
Keyword(s):  
High Speed ◽  
Electronic Portal Imaging Device ◽  
Imaging Device ◽  
Portal Imaging ◽  
Electronic Portal Imaging

scholarly journals Dosimetric Characterization of the Dual Layer MLC System for an O-Ring Linear Accelerator

2019 ◽  
Vol 18 ◽  
pp. 153303381988364 ◽  
Author(s):  
Michele M. Kim ◽  
Douglas Bollinger ◽  
Chris Kennedy ◽  
Wei Zou ◽  
Ryan Scheuermann ◽  
...  
Keyword(s):  
Linear Accelerator ◽  
Multileaf Collimator ◽  
Electronic Portal Imaging Device ◽  
Imaging Device ◽  
Portal Imaging ◽  
Electronic Portal Imaging ◽  
Flattening Filter Free ◽  
Flattening Filter ◽  
Dosimetric Leaf Gap

The Halcyon is Varian’s latest linear accelerator that offers a single 6X flattening-filter-free beam with a jawless design that features a new dual layer multileaf collimator system with faster speed and reduced transmission. Dosimetric characteristics of the dual layer multileaf collimator system including transmission, dosimetric leaf gap, and tongue and groove effects were measured. Ionization chambers, diode arrays, and an electronic portal imaging device were used to measure various multileaf collimator characteristics. Transmission through both multileaf collimator banks was found to be 0.008%, while the distal and proximal banks alone had transmission values of 0.4%. The penumbra was slightly sharper for fields using only the distal multileaf collimator bank but found to be largely independent of leaf position with values between 2.7 to 3.0 mm at dmax for the combined multileaf collimator banks. The dosimetric leaf gap was measured for the proximal and distal multileaf collimator banks both individually and together and found to have values of −0.216 mm, −0.225 mm, and 0.964 mm, respectively. Measurements of dosimetric leaf gap at the leaf edge and midline were also performed. Tongue and groove effects were investigated with both the electronic portal imaging device and a 2-dimensional array of diodes.

Sign in / Sign up

Export Citation Format

Share Document