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SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy

Publication ,  Conference
O'daniel, J; Mcmahon, R; Chang, Z; Yan, H; Sakhalkar, H; Das, S; wu, Q; Yin, F
Published in: Medical Physics
January 1, 2009

Purpose: To develop a patient‐specific quality assurance protocol for RapidArc™ radiotherapy. Method and Materials: Following the commissioning of RapidArc™ treatment delivery, we tested several methods of patient‐specific quality assurance (QA). Ion chamber and film measurements were used as the “gold standard”. One ion chamber measurement was taken in a region of low‐dose gradient. Four film measurements were taken in three planes: axial, sagittal, coronal, and a coronal180° (testing setup uncertainty). Measurements were also taken using the Matrixx® device (IBA Dosimetry, Bartlett, TN) in two orientations, sagittal and coronal. The Matrixx® consists of a 24×24cm2 grid of ion chambers, providing a 2D absolute dose comparison. All plans were designed and calculated using Eclipse (Varian Medical Systems, Palo Alto, CA). Eleven patient plans were evaluated, consisting of 4 brain, 1 head&neck boost, and 6 prostate radiotherapy treatments. Results: Ion chamber measurements were typically ∼2% greater than those predicted by Eclipse. Using a gamma index with 3%, 3mm, 5% threshold criteria, 88% of films had gamma pass rates of >90%. Three of 7 axial films failed, but passed with thresholds of 30–40%. Similarly, Matrixx® measurements had gamma pass rates of >90% for 100% of measurements. The average reading of 4 Matrixx ion chambers was significantly correlated with the single ion chamber results (Pearson correlation coefficient = 0.839, p = 0.002), and the 2D Matrixx results agreed well with film measurements (gamma pass rate >90% for 10 of 11 comparisons). Conclusion: These QA measurements produced good agreement between planned and measured doses. Through utilizing ion chamber and film measurements, we have gained confidence in the Matrixx® for RapidArc QA. The chosen passing criteria were +/−3% for ion chamber readings, and gamma passing rates of >90% for film and Matrixx® with 3%, 3mm, and 5% threshold. © 2009, American Association of Physicists in Medicine. All rights reserved.

Duke Scholars

Published In

Medical Physics

DOI

ISSN

0094-2405

Publication Date

January 1, 2009

Volume

36

Issue

6

Start / End Page

2593 / 2594

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
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O’daniel, J., Mcmahon, R., Chang, Z., Yan, H., Sakhalkar, H., Das, S., … Yin, F. (2009). SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy. In Medical Physics (Vol. 36, pp. 2593–2594). https://doi.org/10.1118/1.3181794
O’daniel, J., R. Mcmahon, Z. Chang, H. Yan, H. Sakhalkar, S. Das, Q. wu, and F. Yin. “SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy.” In Medical Physics, 36:2593–94, 2009. https://doi.org/10.1118/1.3181794.
O’daniel J, Mcmahon R, Chang Z, Yan H, Sakhalkar H, Das S, et al. SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy. In: Medical Physics. 2009. p. 2593–4.
O’daniel, J., et al. “SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy.” Medical Physics, vol. 36, no. 6, 2009, pp. 2593–94. Scopus, doi:10.1118/1.3181794.
O’daniel J, Mcmahon R, Chang Z, Yan H, Sakhalkar H, Das S, wu Q, Yin F. SU‐FF‐T‐314: Patient‐Specific Quality Assurance Techniques for RapidArc Radiotherapy. Medical Physics. 2009. p. 2593–2594.

Published In

Medical Physics

DOI

ISSN

0094-2405

Publication Date

January 1, 2009

Volume

36

Issue

6

Start / End Page

2593 / 2594

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences