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Evaluation of integrated respiratory gating systems on a Novalis Tx system

Publication ,  Journal Article
Chang, Z; Liu, TH; Cai, J; Chen, Q; Wang, Z; Yin, FF
Published in: Journal of Applied Clinical Medical Physics
January 1, 2011

The purpose of this study was to investigate the accuracy of motion tracking and radiation delivery control of integrated gating systems on a Novalis Tx system. The study was performed on a Novalis Tx system, which is equipped with Varian Real-time Position Management (RPM) system, and BrainLAB ExacTrac gating systems. In this study, the two systems were assessed on accuracy of both motion tracking and radiation delivery control. To evaluate motion tracking, two artificial motion profiles and five patients' respiratory profiles were used. The motion trajectories acquired by the two gating systems were compared against the references. To assess radiation delivery control, time delays were measured using a single-exposure method. More specifically, radiation is delivered with a 4 mm diameter cone within the phase range of 10%-45% for the BrainLAB ExacTrac system, and within the phase range of 0%-25% for the Varian RPM system during expiration, each for three times. Radiochromic films were used to record the radiation exposures and to calculate the time delays. In the work, the discrepancies were quantified using the parameters of mean and standard deviation (SD). Pearson's product-moment correlational analysis was used to test correlation of the data, which is quantified using a parameter of r. The trajectory profiles acquired by the gating systems show good agreement with those reference profiles. A quantitative analysis shows that the average mean discrepancies between BrainLAB ExacTrac system and known references are 1.5 mm and 1.9 mm for artificial and patient profiles, with the maximum motion amplitude of 28.0 mm. As for the Varian RPM system, the corresponding average mean discrepancies are 1.1 mm and 1.7 mm for artificial and patient profiles. With the proposed single-exposure method, the time delays are found to be 0.20 ± 0.03 seconds and 0.09 ± 0.01 seconds for BrainLAB ExacTrac and Varian RPM systems, respectively. The results indicate the systems can track motion and control radiation delivery with reasonable accuracy. The proposed single-exposure method has been demonstrated to be feasible in measuring time delay efficiently.

Duke Scholars

Published In

Journal of Applied Clinical Medical Physics

DOI

EISSN

1526-9914

Publication Date

January 1, 2011

Volume

12

Issue

3

Start / End Page

71 / 79

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 3208 Medical physiology
  • 1116 Medical Physiology
  • 1103 Clinical Sciences
  • 0299 Other Physical Sciences
 

Citation

APA
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ICMJE
MLA
NLM
Chang, Z., Liu, T. H., Cai, J., Chen, Q., Wang, Z., & Yin, F. F. (2011). Evaluation of integrated respiratory gating systems on a Novalis Tx system. Journal of Applied Clinical Medical Physics, 12(3), 71–79. https://doi.org/10.1120/jacmp.v12i3.3495
Chang, Z., T. H. Liu, J. Cai, Q. Chen, Z. Wang, and F. F. Yin. “Evaluation of integrated respiratory gating systems on a Novalis Tx system.” Journal of Applied Clinical Medical Physics 12, no. 3 (January 1, 2011): 71–79. https://doi.org/10.1120/jacmp.v12i3.3495.
Chang Z, Liu TH, Cai J, Chen Q, Wang Z, Yin FF. Evaluation of integrated respiratory gating systems on a Novalis Tx system. Journal of Applied Clinical Medical Physics. 2011 Jan 1;12(3):71–9.
Chang, Z., et al. “Evaluation of integrated respiratory gating systems on a Novalis Tx system.” Journal of Applied Clinical Medical Physics, vol. 12, no. 3, Jan. 2011, pp. 71–79. Scopus, doi:10.1120/jacmp.v12i3.3495.
Chang Z, Liu TH, Cai J, Chen Q, Wang Z, Yin FF. Evaluation of integrated respiratory gating systems on a Novalis Tx system. Journal of Applied Clinical Medical Physics. 2011 Jan 1;12(3):71–79.

Published In

Journal of Applied Clinical Medical Physics

DOI

EISSN

1526-9914

Publication Date

January 1, 2011

Volume

12

Issue

3

Start / End Page

71 / 79

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 3208 Medical physiology
  • 1116 Medical Physiology
  • 1103 Clinical Sciences
  • 0299 Other Physical Sciences