ESTRO 2024 - Abstract Book

S4787

Physics - Quality assurance and auditing

ESTRO 2024

Conclusion:

The study established TL and AL values tailored to various anatomical regions at our institution, based on the gamma passing criteria of 3% dose-difference and 3mm dose-to-agreement. Because portal dosimetry has a higher spatial resolution, easier setup, real-time verification, less sensitivity to setup errors and better accuracy, it has become the standard technique in our department for PSQA. We have set TL for Head&Neck, Thoracic and pelvis plans of 96.6%, 98.8% and 99.2% respectively for both VMAT and IMRT treatments. UCI plans to implement a new gamma-pass criteria of 3% dose-difference and 2mm dose-to-agreement, recommended by AAPM TG-218 for portal dosimetry.

Keywords: IMRT/VMAT, Patient-specific QA, Tolerance limits

References:

1) Moyed Miften, Arthur Olch, Dimitris Mihailidis, et al: Tolerance limits and methodologies for IMRT measurement based verification QA: Recommendations of AAPM Task Group No. 218: Med.Phys.45(4), April 2018

2) Taweap Sanghangthum, Sivalee Suriyapee, Gwe-Ya Kim and Todd Pawlicki: A method of setting limits for the purpose of quality assurance Phys. Med. Biol. 58 (2013) 7025–7037

3) Yoshinobu Shimohigashi, Fujio Araki, Hirofumi Tominaga, et al: Angular dependence correction of MatriXX and its application to composite dose verification J. Appl. Clin Med Phys, Vol. 13, no. 5, 2012

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