Range resolution and reproducibility of a dedicated phantom for proton PBS daily quality assurance

Placidi, L.; Togno, Michele; Weber, Damien Charles; Lomax, Anthony; Hrbáček, Jan

doi:10.1016/j.zemedi.2018.02.001

Cited by 15 publications

(17 citation statements)

References 17 publications

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“…For PBS, the ranges of single-layer beams should be verified. 98 When a large field is applied, a plane-parallel ionization chamber (with a high spatial resolution for distal fall off) may be used for range measurements. The chamber should be positioned in a sufficiently thick solid phantom material, such that the front plate is positioned in the distal fall-off gradient.…”

Section: A2 Rangementioning

confidence: 99%

AAPM task group 224: Comprehensive proton therapy machine quality assurance

et al. 2019

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Purpose: Task Group (TG) 224 was established by the American Association of Physicists in Medicine's Science Council under the Radiation Therapy Committee and Work Group on Particle Beams. The group was charged with developing comprehensive quality assurance (QA) guidelines and recommendations for the three commonly employed proton therapy techniques for beam delivery: scattering, uniform scanning, and pencil beam scanning. This report supplements established QA guidelines for therapy machine performance for other widely used modalities, such as photons and electrons (TG 142, TG 40, TG 24, TG 22, TG 179, and Medical Physics Practice Guideline 2a) and shares their aims of ensuring the safe, accurate, and consistent delivery of radiation therapy dose distributions to patients. Methods: To provide a basis from which machine‐specific QA procedures can be developed, the report first describes the different delivery techniques and highlights the salient components of the related machine hardware. Depending on the particular machine hardware, certain procedures may be more or less important, and each institution should investigate its own situation. Results: In lieu of such investigations, this report identifies common beam parameters that are typically checked, along with the typical frequencies of those checks (daily, weekly, monthly, or annually). The rationale for choosing these checks and their frequencies is briefly described. Short descriptions of suggested tools and procedures for completing some of the periodic QA checks are also presented. Conclusion: Recommended tolerance limits for each of the recommended QA checks are tabulated, and are based on the literature and on consensus data from the clinical proton experience of the task group members. We hope that this and other reports will serve as a reference for clinical physicists wishing either to establish a proton therapy QA program or to evaluate an existing one.

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Section: A2 Rangementioning

confidence: 99%

AAPM task group 224: Comprehensive proton therapy machine quality assurance

et al. 2019

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“…Lamber et al., for instance, observed that their daily beam range varied to within 0.5 mm using the Sun Nuclear Daily QA3. Placidi et al . and Ding et al., also studied the daily proton beam range variation using IBA Lynx with sphinx phantom and Sun Nuclear rf‐Daily QA3, respectively, and both reported a maximum deviation in range of less than 0.5 mm.…”

Section: Resultsmentioning

confidence: 99%

“…Similar study was presented by Ding et al 7 using the rf-Daily QA3 for daily beam range check of their IBA cyclotron. Placidi et al 8 used a commercially available Sphinx phantom with the IBA Lynx to perform the daily beam range check of their cyclotron accelerator.…”

Section: Introductionmentioning

confidence: 99%

Technical Note: Use of commercial multilayer Faraday cup for offline daily beam range verification at the McLaren Proton Therapy Center

et al. 2019

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Purpose Daily verification of the proton beam range in proton radiation therapy is a vital part of the quality assurance (QA) program. The objective of this work is to study the use of a multilayer Faraday cup (MLFC) to perform a quick and precise daily range verification of proton beams produced by a synchrotron. Methods Proton beam depth dose measurements were performed at room iso‐center in water using PTW water tank and Bragg Peak ion chamber. The IBA Giraffe, calibrated against the water tank data, was used to measure the water equivalent thickness (WET) of the sample copper plates. The WET measurements provided the range calibration factors for the MLFC. To establish a baseline for in room measurements, range measurements for energies from 70 to 250 MeV in steps of 10 MeV were performed using the Pyramid MLFC at room iso‐center. For the daily range verification measurements, the MLFC is permanently placed at the end of the beam line, inside the accelerator vault. The daily range constancy is performed for five representative beam energies; namely 70, 100, 150, 200, and 250 MeV. Data collected over a period of more than 100 days are analyzed and presented. Results The measured WET values of the copper plates increased with increasing energy. The centroid channel number in the MLFC where the protons stop, was converted to depth in water and compared to the depth of the distal 80% (d80) obtained from the water tank measurements. The depths agreed to within 2 mm, with the maximum deviation of 1.97 mm observed for 250 MeV beam. The daily variation in the ranges measured by the MLFC was within ±0.5 mm. The total time to verify five proton beam ranges varies between 4 and 5 min. Conclusion Based on the result of our measurements, the MLFC can be used for a daily range constancy check with submillimeter accuracy. It is a quick and simple method to perform range constancy verification on a daily basis.

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“…For daily PBS QA, it suggested tests of dose per monitor unit, range, measurement of Spread-out Bragg Peak (SOBP) width, spot delivery constancy, and x-ray/proton beam isocenter coincidence. For these tests, there are several home-made and commercial daily PBS QA devices used in the different clinics [8][9][10][11][12][13]. A new flat-panel based compact PBS daily QA prototype system, named Sphinx Compact was obtained from IBA Dosimetry (Schwarzenbruck, Germany), for a clinical beta evaluation at the University of Florida Health Proton Therapy Institute.…”

Section: Introductionmentioning

confidence: 99%

“…A new flat-panel based compact PBS daily QA prototype system, named Sphinx Compact was obtained from IBA Dosimetry (Schwarzenbruck, Germany), for a clinical beta evaluation at the University of Florida Health Proton Therapy Institute. This device, composed of a flat-panel detector combined with different plastic blocks, is more compact and modular than the Sphinx + Lynx system [12,13]. Only one correction file (for pixel sensitivity variation, background and bad pixles) has to be applied to the response of the new device.…”

Section: Introductionmentioning

confidence: 99%