PO-1576 A novel anthropomorphic phantom for the commissioning of MLC-based stereotactic radiosurgery.

Brown, Tracy L.; Beck, Cristiane; Holloway, Caroline L.; Kerns, J; Fagerstrom, Jessica M.; Kaurin, D.G.; Kielar, K

doi:10.1016/s0167-8140(21)08027-0

Cited by 2 publications

(11 citation statements)

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“…However, CT/MRI registration accuracy for this cassette was verified during the design evaluation of the phantom. 17 …”

Section: Methodsmentioning

confidence: 99%

“…The second film design was a prototype design developed for the initial testing of the phantom. 17 This prototype design did not have the circular and rectangular fiducial holes shown in Figure 3 and the slit, allowing the film pieces to interlock, terminated exactly at the center of each film piece; otherwise, the design was the same as shown in this figure. The film was digitized 3–7 days after irradiation using an Epson Perfection V750 Pro flatbed scanner (Epson America, Los Alamitos, CA).…”

Section: Methodsmentioning

confidence: 99%

“…The method of using the slit as a registration basis was validated previously. 17 Following the manual registration, DoseLab optimized this alignment by applying additional shifts to the relative position of the calculated and measured dose distributions. These “auto‐registration shifts” were used as a metric for evaluating the targeting accuracy of the SRS treatments.…”

Section: Methodsmentioning

confidence: 99%

“…The phantom design was initially evaluated by Northwest Medical Physics Center (NMPC) and an MLC‐based, SRS end‐to‐end procedure for this phantom was developed for TrueBeam and Edge machines. 17 , 18 This procedure has now been performed for six linacs, at 6‐ and 10‐MV flattening filter‐free (FFF) energies, for the purposes of establishing baseline commissioning criteria for SRS measurements with this phantom. Data collection from multiple linacs using a standardized procedure permits the definition of a specific set of dosimetric and geometric commissioning criteria for prescribed tests on these machines, within the boundary conditions of published tolerances.…”

Section: Introductionmentioning

confidence: 99%

“…Two spherical targets—1 and 2 cm in diameter—can be used for treatment planning. The phantom design was initially evaluated by Northwest Medical Physics Center (NMPC) and an MLC‐based, SRS end‐to‐end procedure for this phantom was developed for TrueBeam and Edge machines 17,18 . This procedure has now been performed for six linacs, at 6‐ and 10‐MV flattening filter‐free (FFF) energies, for the purposes of establishing baseline commissioning criteria for SRS measurements with this phantom.…”

Section: Introductionmentioning

confidence: 99%

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Determination of commissioning criteria for multileaf‐collimator, stereotactic radiosurgery treatments on Varian TrueBeam and Edge machines using a novel anthropomorphic phantom

Brown¹,

Fagerstrom²,

Beck³

et al. 2022

J Applied Clin Med Phys

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An anthropomorphic phantom has been developed by Varian Medical Systems for commissioning multileaf -collimator (MLC), stereotactic radiosurgery (SRS) treatments on Varian TrueBeam and Edge linear accelerators. Northwest Medical Physics Center (NMPC) has collected end-to-end data on these machines, at six independent clinical sites, to establish baseline dosimetric and geometric commissioning criteria for SRS measurements with this phantom. The Varian phantom is designed to accommodate four interchangeable target cassettes, each designed for a specific quality assurance function. End-to-end measurements utilized the phantom to verify the coincidence of treatment isocenter with a hidden target in a Winston-Lutz cassette after localization using cone-beam computed tomography (CBCT). Dose delivery to single target (2 cm) and singleisocenter, multitarget (2 and 1 cm) geometries was verified using ionization chamber and EBT3 film cassettes. A nominal dose of 16 Gy was prescribed for each plan using a site's standard beam geometry for SRS cases.Measurements were performed with three Millennium and three high-definition MLC machines at beam energies of 6-MV and 10-MV flattening-filter-free energies. Each clinical site followed a standardized procedure for phantom simulation, treatment planning, quality assurance, and treatment delivery. All treatment planning and delivery was performed using ARIA oncology information system and Eclipse treatment planning software. The isocenter measurements and irradiated film were analyzed using DoseLab quality assurance software; gamma criteria of 3%/1 mm, 3%/0.5 mm, and 2%/1 mm were applied for film analysis. Based on the data acquired in this work, the recommended commissioning criteria for endto-end SRS measurements with the Varian phantom are as follows: coincidence of treatment isocenter and CBCT-aligned hidden target < 1 mm, agreement of measured chamber dose with calculated dose ≤ 5%, and film gamma passing > 90% for gamma criteria of 3%/1 mm after DoseLab auto-registration shifts ≤ 1 mm in any direction.

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“…However, CT/MRI registration accuracy for this cassette was verified during the design evaluation of the phantom. 17 …”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Determination of commissioning criteria for multileaf‐collimator, stereotactic radiosurgery treatments on Varian TrueBeam and Edge machines using a novel anthropomorphic phantom

Brown¹,

Fagerstrom²,

Beck³

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

Overview of medical physics education and research programs in a non‐academic environment

Fagerstrom,

Brown,

Kaurin

et al. 2023

J Applied Clin Med Phys

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Northwest Medical Physics Center (NMPC) is a nonprofit organization that provides clinical physics support to over 35 radiation therapy facilities concentrated in the Pacific Northwest. Although clinical service is the primary function of NMPC, the diverse array of clinical sites and physics expertise has allowed for the establishment of structured education and research programs, which are complementary to the organization's clinical mission. Three clinical training programs have been developed at NMPC: a therapy medical physics residency program accredited by the Commission on Accreditation of Medical Physics Education Programs (CAMPEP), an Applied Physics Technologist (APT) program, and a summer undergraduate internship program. A partnership has also been established with a major radiation oncology clinical vendor for the purposes of validating and testing new clinical devices across multiple facilities. These programs are managed by a dedicated education and research team at NMPC, made up of four qualified medical physicists (QMPs). The education and research work has made a significant contribution to the organization's clinical mission, and it has provided new training opportunities for early‐career physicists across many different clinical environments. Education and research can be incorporated into nonacademic clinical environments, improving the quality of patient care, and increasing the number and type of training opportunities available for medical physicists.

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PO-1576 A novel anthropomorphic phantom for the commissioning of MLC-based stereotactic radiosurgery.

Cited by 2 publications

References 0 publications

Determination of commissioning criteria for multileaf‐collimator, stereotactic radiosurgery treatments on Varian TrueBeam and Edge machines using a novel anthropomorphic phantom

Determination of commissioning criteria for multileaf‐collimator, stereotactic radiosurgery treatments on Varian TrueBeam and Edge machines using a novel anthropomorphic phantom

Overview of medical physics education and research programs in a non‐academic environment

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