An empirical relationship for determining photon beam quality in TG-21 from a ratio of percent depth doses.

@article{Followill1998AnER,
  title={An empirical relationship for determining photon beam quality in TG-21 from a ratio of percent depth doses.},
  author={David S. Followill and Ramesh C. Tailor and Victor M. Tello and William Hanson},
  journal={Medical physics},
  year={1998},
  volume={25 7 Pt 1},
  pages={1202-5}
}
A key component of the Radiological Physics Center's (RPC) on-site dosimetry review visits are photon beam calibrations for which determination of the energy of the x ray is a key element. The ratio of ionizations, TPR20/TPR10, for a 10 cm x 10 cm field at depths of 20 and 10 cm for a constant SCD is used as a quantitative measure of beam quality in the Task Group 21 protocol. The RPC has measured both TPR20/TPR10 and the corresponding ratio of percent depth dose (D20/D10) at a constant SSD for… CONTINUE READING