skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: SU-E-T-662: Quick and Efficient Daily QA for Compact PBS Proton Therapy Machine

Abstract

Purpose: As proton therapy machines become widespread the need for a quick simple routine daily QA like that for linear accelerators becomes more important. Willis-Knighton has developed an accurate and efficient daily QA that can be performed in 15 minutes. Methods: A holder for a 2D ionization chamber array (MatriXX PT) was created that is indexed to the couch to allow for quick setup, lasers accuracy with respect to beam isocenter, and couch reproducibility. Image position/reposition was performed to check Isocentricity accuracy by placing BBs on the MatriXX. The couch coordinates are compared to that of commissioning. Laser positions were confirmed with the MatriXX isocenter. After IGRT, three beams were separately delivered according to setup. For the first beam, range shifter was inserted and dose at R90, field size, flatness and symmetry in X and Y direction was measured. R90 was used so any minor changes in the range shifter can be detected. For the open beam, dose at center of SOBP, flatness and symmetry in X and Y direction was measured. Field size was measured in ±X and ±Y direction at FWHM. This is measured so any variation in spot size will be detected. For the third beam additionalmore » solid water was added and dose at R50 was measured so that any variation in beam energy will be detected. Basic mechanical and safety checks were also performed. Results: Medical physicists were able to complete the daily QA and reduce the time by half to two-third from initial daily QA procedure. All the values measured were within tolerance of that of the baseline which was established from water tank and initial MatriXX measurements. Conclusion: The change in daily QA procedure resulted in quick and easy setup and was able to measure all the basic functionality of the proton therapy PBS.« less

Authors:
; ; ; ; ; ;  [1]
  1. Willis-Knighton Medical Center, Shreveport, LA (United States)
Publication Date:
OSTI Identifier:
22538170
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 42; Journal Issue: 6; Other Information: (c) 2015 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; COMMISSIONING; IONIZATION CHAMBERS; LINEAR ACCELERATORS; PROTON BEAMS; QUALITY ASSURANCE; RADIATION DOSES; RADIOTHERAPY

Citation Formats

Patel, B, Syh, J, Ding, X, Syh, J, Song, X, Freund, D, and Wu, H. SU-E-T-662: Quick and Efficient Daily QA for Compact PBS Proton Therapy Machine. United States: N. p., 2015. Web. doi:10.1118/1.4925025.
Patel, B, Syh, J, Ding, X, Syh, J, Song, X, Freund, D, & Wu, H. SU-E-T-662: Quick and Efficient Daily QA for Compact PBS Proton Therapy Machine. United States. doi:10.1118/1.4925025.
Patel, B, Syh, J, Ding, X, Syh, J, Song, X, Freund, D, and Wu, H. Mon . "SU-E-T-662: Quick and Efficient Daily QA for Compact PBS Proton Therapy Machine". United States. doi:10.1118/1.4925025.
@article{osti_22538170,
title = {SU-E-T-662: Quick and Efficient Daily QA for Compact PBS Proton Therapy Machine},
author = {Patel, B and Syh, J and Ding, X and Syh, J and Song, X and Freund, D and Wu, H},
abstractNote = {Purpose: As proton therapy machines become widespread the need for a quick simple routine daily QA like that for linear accelerators becomes more important. Willis-Knighton has developed an accurate and efficient daily QA that can be performed in 15 minutes. Methods: A holder for a 2D ionization chamber array (MatriXX PT) was created that is indexed to the couch to allow for quick setup, lasers accuracy with respect to beam isocenter, and couch reproducibility. Image position/reposition was performed to check Isocentricity accuracy by placing BBs on the MatriXX. The couch coordinates are compared to that of commissioning. Laser positions were confirmed with the MatriXX isocenter. After IGRT, three beams were separately delivered according to setup. For the first beam, range shifter was inserted and dose at R90, field size, flatness and symmetry in X and Y direction was measured. R90 was used so any minor changes in the range shifter can be detected. For the open beam, dose at center of SOBP, flatness and symmetry in X and Y direction was measured. Field size was measured in ±X and ±Y direction at FWHM. This is measured so any variation in spot size will be detected. For the third beam additional solid water was added and dose at R50 was measured so that any variation in beam energy will be detected. Basic mechanical and safety checks were also performed. Results: Medical physicists were able to complete the daily QA and reduce the time by half to two-third from initial daily QA procedure. All the values measured were within tolerance of that of the baseline which was established from water tank and initial MatriXX measurements. Conclusion: The change in daily QA procedure resulted in quick and easy setup and was able to measure all the basic functionality of the proton therapy PBS.},
doi = {10.1118/1.4925025},
journal = {Medical Physics},
number = 6,
volume = 42,
place = {United States},
year = {Mon Jun 15 00:00:00 EDT 2015},
month = {Mon Jun 15 00:00:00 EDT 2015}
}