Addendum to the AAPM's TG-51 protocol for clinical reference dosimetry of high-energy photon beams

作者：McEwen Malcolm^*; DeWerd Larry; Ibbott Geoffrey; Followill David; Rogers David W O; Seltzer Stephen; Seuntjens Jan

来源：Medical Physics, 2014, 41(4): 041501.

DOI：10.1118/1.4866223

• photon beams
• dosimetry protocol
• ionization chamber
• beam quality conversion factors
• kQ
• uncertainty analysis
• absorbed dose calibration coefficients

An addendum to the AAPM's TG-51 protocol for the determination of absorbed dose to water in megavoltage photon beams is presented. This addendum continues the procedure laid out in TG-51 but new k(Q) data for photon beams, based on Monte Carlo simulations, are presented and recommendations are given to improve the accuracy and consistency of the protocol's implementation. The components of the uncertainty budget in determining absorbed dose to water at the reference point are introduced and the magnitude of each component discussed. Finally, the consistency of experimental determination of N-D,N-w coefficients is discussed. It is expected that the implementation of this addendum will be straightforward, assuming that the user is already familiar with TG-51. The changes introduced by this report are generally minor, although new recommendations could result in procedural changes for individual users. It is expected that the effort on the medical physicist's part to implement this addendum will not be significant and could be done as part of the annual linac calibration.

• 出版日期2014-4