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Evaluation of the efficiency and effectiveness of independent dose calculation followed by machine log file analysis against conventional measurement based IMRT QA.
J Appl Clin Med Phys 2012; 13(5):3837JA

Abstract

Experimental methods are commonly used for patient-specific IMRT delivery verification. There are a variety of IMRT QA techniques which have been proposed and clinically used with a common understanding that not one single method can detect all possible errors. The aim of this work was to compare the efficiency and effectiveness of independent dose calculation followed by machine log file analysis to conventional measurement-based methods in detecting errors in IMRT delivery. Sixteen IMRT treatment plans (5 head-and-neck, 3 rectum, 3 breast, and 5 prostate plans) created with a commercial treatment planning system (TPS) were recalculated on a QA phantom. All treatment plans underwent ion chamber (IC) and 2D diode array measurements. The same set of plans was also recomputed with another commercial treatment planning system and the two sets of calculations were compared. The deviations between dosimetric measurements and independent dose calculation were evaluated. The comparisons included evaluations of DVHs and point doses calculated by the two TPS systems. Machine log files were captured during pretreatment composite point dose measurements and analyzed to verify data transfer and performance of the delivery machine. Average deviation between IC measurements and point dose calculations with the two TPSs for head-and-neck plans were 1.2 ± 1.3% and 1.4 ± 1.6%, respectively. For 2D diode array measurements, the mean gamma value with 3% dose difference and 3 mm distance-to-agreement was within 1.5% for 13 of 16 plans. The mean 3D dose differences calculated from two TPSs were within 3% for head-and-neck cases and within 2% for other plans. The machine log file analysis showed that the gantry angle, jaw position, collimator angle, and MUs were consistent as planned, and maximal MLC position error was less than 0.5 mm. The independent dose calculation followed by the machine log analysis takes an average 47 ± 6 minutes, while the experimental approach (using IC and 2D diode array measurements) takes an average about 2 hours in our clinic. Independent dose calculation followed by machine log file analysis can be a reliable tool to verify IMRT treatments. Additionally, independent dose calculations have the potential to identify several problems (heterogeneity calculations, data corruptions, system failures) with the primary TPS, which generally are not identifiable with a measurement-based approach. Additionally, machine log file analysis can identify many problems (gantry, collimator, jaw setting) which also may not be detected with a measurement-based approach. Machine log file analysis could also detect performance problems for individual MLC leaves which could be masked in the analysis of a measured fluence.

Authors+Show Affiliations

Department of Radiation Oncology,1 Washington University School of Medicine, St. Louis, MO, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Evaluation Studies
Journal Article

Language

eng

PubMed ID

22955649

Citation

Sun, Baozhou, et al. "Evaluation of the Efficiency and Effectiveness of Independent Dose Calculation Followed By Machine Log File Analysis Against Conventional Measurement Based IMRT QA." Journal of Applied Clinical Medical Physics, vol. 13, no. 5, 2012, p. 3837.
Sun B, Rangaraj D, Boddu S, et al. Evaluation of the efficiency and effectiveness of independent dose calculation followed by machine log file analysis against conventional measurement based IMRT QA. J Appl Clin Med Phys. 2012;13(5):3837.
Sun, B., Rangaraj, D., Boddu, S., Goddu, M., Yang, D., Palaniswaamy, G., ... Mutic, S. (2012). Evaluation of the efficiency and effectiveness of independent dose calculation followed by machine log file analysis against conventional measurement based IMRT QA. Journal of Applied Clinical Medical Physics, 13(5), p. 3837. doi:10.1120/jacmp.v13i5.3837.
Sun B, et al. Evaluation of the Efficiency and Effectiveness of Independent Dose Calculation Followed By Machine Log File Analysis Against Conventional Measurement Based IMRT QA. J Appl Clin Med Phys. 2012 Sep 6;13(5):3837. PubMed PMID: 22955649.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Evaluation of the efficiency and effectiveness of independent dose calculation followed by machine log file analysis against conventional measurement based IMRT QA. AU - Sun,Baozhou, AU - Rangaraj,Dharanipathy, AU - Boddu,Sunita, AU - Goddu,Murty, AU - Yang,Deshan, AU - Palaniswaamy,Geethpriya, AU - Yaddanapudi,Sridhar, AU - Wooten,Omar, AU - Mutic,Sasa, Y1 - 2012/09/06/ PY - 2011/12/07/received PY - 2012/05/30/accepted PY - 2012/04/25/revised PY - 2012/9/8/entrez PY - 2012/9/8/pubmed PY - 2013/1/26/medline SP - 3837 EP - 3837 JF - Journal of applied clinical medical physics JO - J Appl Clin Med Phys VL - 13 IS - 5 N2 - Experimental methods are commonly used for patient-specific IMRT delivery verification. There are a variety of IMRT QA techniques which have been proposed and clinically used with a common understanding that not one single method can detect all possible errors. The aim of this work was to compare the efficiency and effectiveness of independent dose calculation followed by machine log file analysis to conventional measurement-based methods in detecting errors in IMRT delivery. Sixteen IMRT treatment plans (5 head-and-neck, 3 rectum, 3 breast, and 5 prostate plans) created with a commercial treatment planning system (TPS) were recalculated on a QA phantom. All treatment plans underwent ion chamber (IC) and 2D diode array measurements. The same set of plans was also recomputed with another commercial treatment planning system and the two sets of calculations were compared. The deviations between dosimetric measurements and independent dose calculation were evaluated. The comparisons included evaluations of DVHs and point doses calculated by the two TPS systems. Machine log files were captured during pretreatment composite point dose measurements and analyzed to verify data transfer and performance of the delivery machine. Average deviation between IC measurements and point dose calculations with the two TPSs for head-and-neck plans were 1.2 ± 1.3% and 1.4 ± 1.6%, respectively. For 2D diode array measurements, the mean gamma value with 3% dose difference and 3 mm distance-to-agreement was within 1.5% for 13 of 16 plans. The mean 3D dose differences calculated from two TPSs were within 3% for head-and-neck cases and within 2% for other plans. The machine log file analysis showed that the gantry angle, jaw position, collimator angle, and MUs were consistent as planned, and maximal MLC position error was less than 0.5 mm. The independent dose calculation followed by the machine log analysis takes an average 47 ± 6 minutes, while the experimental approach (using IC and 2D diode array measurements) takes an average about 2 hours in our clinic. Independent dose calculation followed by machine log file analysis can be a reliable tool to verify IMRT treatments. Additionally, independent dose calculations have the potential to identify several problems (heterogeneity calculations, data corruptions, system failures) with the primary TPS, which generally are not identifiable with a measurement-based approach. Additionally, machine log file analysis can identify many problems (gantry, collimator, jaw setting) which also may not be detected with a measurement-based approach. Machine log file analysis could also detect performance problems for individual MLC leaves which could be masked in the analysis of a measured fluence. SN - 1526-9914 UR - https://www.unboundmedicine.com/medline/citation/22955649/Evaluation_of_the_efficiency_and_effectiveness_of_independent_dose_calculation_followed_by_machine_log_file_analysis_against_conventional_measurement_based_IMRT_QA_ L2 - https://doi.org/10.1120/jacmp.v13i5.3837 DB - PRIME DP - Unbound Medicine ER -