Recently published
Medical Physics Practice Guideline 5.a. (MPPG 5.a.) by American Association of
Physicists in Medicine (AAPM) sets the minimum requirements for treatment
planning system (TPS) dose algorithm commissioning and quality assurance (QA).
The guideline recommends some validation tests and tolerances based primarily
on published AAPM task group reports and the criteria used by IROC Houston. We
performed the commissioning and validation of the dose algorithms for both
megavoltage photon and electron beams on three linacs following MPPG 5.a. We
designed the validation experiments in an attempt to highlight the evaluation
method and tolerance criteria recommended by the guideline. It seems that
comparison of dose profiles using in-water scan is an effective technique for
basic photon and electron validation. IMRT/VMAT dose calculation is recommended
to be tested with some TG-119 and clinical cases, but no consensus of the
tolerance exists. Extensive validation tests have provided the better
understanding of the accuracy and limitation of a specific dose calculation
algorithm. We believe that some tests and evaluation criteria given in the
guideline can be further refined.
References
[1]
International Commission on Radiation Units and Measurements (ICRU) (1976) Determination of Absorbed Dose in a Patient Irradiated by Beams of X or Gamma Rays in Radiotherapy Procedures. ICRU Report 24, ICRU, Washington DC, 67.
[2]
American Association of Physicists in Medicine (AAPM) (2004) Tissue in Homogeneity Corrections for Megavoltage Photon Beams. Radiotherapy Committee Task Group 65, Report No. 85, Report of AAPM, Medical Physics Publishing, Madison.
[3]
Smilowitz, J.B., Das, I.J., Feygelman, V., Fraass, B.A., Kry, S.F., Marshall, I.R., Mihailidis, D.N., Ouhib, Z., Ritter, T., Snyder, M.G. and Fairobent, L. (2015) AAPM Medical Physics Practice Guideline 5.a.: Commissioning and QA of Treatment Planning Dose Calculations—Megavoltage Photon and Electron Beams. Journal of Applied Clinical Medical Physics, 16, 57-68.
[4]
Ezzell, G.A., Burmeister, J.W., Dogan, N., et al. (2009) IMRT Commissioning: Multiple Institution Planning and Dosimetry Comparisons, a Report from AAPM Task Group 119. Medical Physics, 36, 5359-5373. https://doi.org/10.1118/1.3238104
[5]
Molineu, A., Hernandez, N., Nguyen, T., Ibbott, G. and Followill, D. (2013) Credentialing Results from IMRT Irradiations of an Anthropomorphic Head and Neck Phantom. Medical Physics, 40, Article ID: 022101. https://doi.org/10.1118/1.4773309
[6]
Ding, G.X., Cygler, J.E., Yu, C.W., et al. (2005) A Comparison of Electron Beam Dose Calculation Accuracy between Treatment Planning Systems Using either a Pencil Beam or a Monte Carlo Algorithm. International Journal of Radiation Oncology*Biology*Physics, 63, 622-633. https://doi.org/10.1016/j.ijrobp.2005.06.016
[7]
Das, I.J., Cheng, C.W., Watts, R.J., et al. (2008) Accelerator Beam Data Commissioning Equipment and Procedures: Report of the TG-106 of the Therapy Physics Committee of the AAPM. Medical Physics, 35, 4186-4215. https://doi.org/10.1118/1.2969070
[8]
Chetty, I.J., Curran, B., Cygler, J.E., et al. (2007) Report of the AAPM Task Group No. 105: Issues Associated with Clinical Implementation of Monte Carlo-Based Photon and Electron External Beam Treatment Planning. Medical Physics, 34, 4818-4853. https://doi.org/10.1118/1.2795842
[9]
Han, T., Mikell, J.K., Salehpour, M. and Mourtada, F. (2011) Dosimetric Comparison of Acuros XB Deterministic Radiation Transport Method with Monte Carlo and Model-Based Convolution Methods in Heterogeneous Media. Medical Physics, 38, 2651-2664. https://doi.org/10.1118/1.3582690
[10]
Ma, C.-M. and Li, J. (2011) Dose Specification for Radiation Therapy: Dose to Water or Dose to Medium? Physics in Medicine and Biology, 56, 3073-3089. https://doi.org/10.1088/0031-9155/56/10/012
[11]
Kry, S.F., Molineu, A., Kerns, J.R., Faught, A.M., Huang, J.Y., et al. (2014) Institutional Patient-Specific IMRT QA Does Not Predict Unacceptable Plan Delivery. International Journal of Radiation Oncology*Biology*Physics, 90, 1195-1201. https://doi.org/10.1016/j.ijrobp.2014.08.334
