




![]() |
Report No. 385 - AAPM WGTG51 Report 385: Addendum to the AAPM's TG-51 protocol for clinical reference dosimetry of high-energy electron beams (2024) Category: Reports An Addendum to the AAPM's TG-51 protocol for the determination of absorbed dose to water is presented for electron beams with energies between 4 MeV and 22 MeV (1.70 cm = R50 = 8.70 cm). This updated formalism allows simplified calibration procedures, including the use of calibrated cylindrical ionization chambers in all electron beams without the use of a gradient correction. New data are provided for electron beams based on Monte Carlo simulations. Implementation guidance is provided. Components of the uncertainty budget in determining absorbed dose to water at the reference depth are discussed. Specifications for a reference-class chamber in electron beams include chamber stability, settling, ion recombination behavior, and polarity dependence. Progress in electron beam reference dosimetry is reviewed. Although this report introduces some major changes (e.g., gradient corrections are implicitly included in the electron beam quality conversion factors), they serve to simplify the calibration procedure. Results for absorbed dose per linac monitor unit are expected to be up to approximately 2 % higher using this Addendum compared to using the original TG-51 protocol. Medical Physics https://doi.org/10.1002/mp.17277 Altmetrics for this report Keywords: absorbed-dose calibration coefficient, beam quality conversion factor, dosimetry protocol, ionization chamber, kQ, uncertainty analysis, electron beam Review and Extension of External Beam Reference Dosimetry Protocols (WGTG51) *Addendum to: Report No. 067 Bryan R. Muir, Stephen D. Davis, Sandeep K. Dhanesar, Yair A. Hillman, Viktor M. Iakovenko, Grace Gwe-Ya Kim, Victor Gabriel Leandro Alves, Yu Lei, Jessica R. Lowenstein, James Renaud, Arman Sarfehnia, Jeffrey V. Siebers, Laurent C. Tantôt Committee Responsible: Calibration Laboratory Accreditation Subcommittee Last Review Date: |