[Report on the 13th European Congress of Radiology (ECR): Comparison of primary proton beams and secondary charged-particles].
Nihon Hoshasen Gijutsu Gakkai Zasshi
; 58(1): 51-2, 2002 Jan.
Article
de Ja
| MEDLINE
| ID: mdl-12527871
ABSTRACT
PURPOSE:
In the proton radiotherapy, primary proton beams contribute to the absorbed dose and the share of secondary charged-particles is small. The purpose is to discuss about the ratio of average dose of primary proton beams and secondary charged-particles.METHODS:
We performed the dosimetry of 70 MeV proton beams in water using ionization chamber. The ratio of average dose for secondary charged-particles in some range shifter was calculated by the dose ratio of primary and scatter. To exclude the influence of lateral secondary charged-particles, the ratio of average dose for secondary charged-particles was extrapolated to zero field size of each.RESULTS:
The ratio of average dose for secondary charged-particles was extrapolated to zero field size by the bi-exponential fit. The ratio of average dose for longitudinal secondary charged-particles for zero fields at each depth is almost the same; the different at the shallow depth is decreased.CONCLUSIONS:
The secondary charged-particles from collimator is affected by the dose of shallow depth. The influence of lateral secondary charged-particles in water phantom was excluded with the extrapolation method for zero field size in each depth.
Recherche sur Google
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Protons
/
Dosimétrie en radiothérapie
/
Particules alpha
Limites:
Humans
Langue:
Ja
Journal:
Nihon Hoshasen Gijutsu Gakkai Zasshi
Année:
2002
Type de document:
Article