Verification of an independent dose calculation method for portal-specific QA of proton and carbon ion beams

Michael F. Moyers; Qianxia Wang; Yu Deng; Hongliang Chen; Zhi Chen; Xiaoli Liu; Nicki Schlegel; Jie Li; Zhuangming Shen; James Lin; Pablo Yepes

Radiation Medicine and Protection (Sep 2022)

Verification of an independent dose calculation method for portal-specific QA of proton and carbon ion beams

Michael F. Moyers,
Qianxia Wang,
Yu Deng,
Hongliang Chen,
Zhi Chen,
Xiaoli Liu,
Nicki Schlegel,
Jie Li,
Zhuangming Shen,
James Lin,
Pablo Yepes

Affiliations

Michael F. Moyers: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China; Corresponding author. Shanghai Proton and Heavy Ion Center, Shanghai 201315, China.
Qianxia Wang: Rice University, Houston, TX, USA
Yu Deng: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Hongliang Chen: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Zhi Chen: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Xiaoli Liu: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Nicki Schlegel: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Jie Li: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Zhuangming Shen: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
James Lin: Shanghai Proton and Heavy Ion Center, Shanghai 201315, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, China
Pablo Yepes: Rice University, Houston, TX, USA

Journal volume & issue: Vol. 3, no. 3
pp. 152 – 157

Abstract

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Objective: To verify the accuracy of an independent dose calculation method, as incorporated into an in-house developed treatment planning system (TPS), for performing quality assurance of dose distributions delivered to a water phantom planned by a clinical TPS. Methods: A Monte Carlo based track repeating algorithm was incorporated into an in-house treatment planning system for proton and carbon ion beams. Calculations were performed in a flat water phantom for both a traditional pencil beam algorithm and a new Monte Carlo algorithm, and then compared to measurements made at multiple depths with a 2D ionization array for 44 patient portals. The comparisons utilized a Gamma analysis. Results: A total of 124 measurements were performed for proton and carbon ion patient portals. Using a small Gamma criteria of 2%/2 mm, an average of 93% and 97% of measurement points passed for each portal for pencil beam and Monte Carlo calculations, respectively. The passing rate was substantially higher for Monte Carlo calculations than for pencil beam calculations for portals that used a range shifter. Conclusions: The implemented independent method has been verified against measurements. The high passing rate with small tolerances leads to the possibility of reducing the number of required quality assurance measurements.

Published in Radiation Medicine and Protection

ISSN: 2666-5557 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Medicine: Medicine (General): Medical physics. Medical radiology. Nuclear medicine
Website: https://www.sciencedirect.com/journal/radiation-medicine-and-protection

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