Table 4 Fluence and average energy of electrons produced by 6 MV photons at different depths of 1.5, 5.0, and 10.0 cm inside the water in open and grid fields. The relative uncertainties in fluence calculations was kept within 1%.
From: Beam quality and the mystery behind the lower percentage depth dose in grid radiation therapy
Field size (cm2) | Depth = 1.5 cm | Depth = 5.0 cm | Depth = 10.0 cm | ||||||
|---|---|---|---|---|---|---|---|---|---|
Open | Brass | Cerrobend | Open | Brass | Cerrobend | Open | Brass | Cerrobend | |
Electron fluence (107/cm2/MU) | |||||||||
10 × 10 | 1.83 | 1.47 | 1.46 | 1.48 | 1.18 | 1.15 | 1.18 | 0.92 | 0.90 |
20 × 20 | 1.87 | 1.52 | 1.49 | 1.51 | 1.20 | 1.17 | 1.20 | 0.93 | 0.91 |
Electron average energy (MeV) | |||||||||
10 × 10 | 1.48 | 1.56 | 1.56 | 1.45 | 1.52 | 1.52 | 1.48 | 1.54 | 1.54 |
20 × 20 | 1.48 | 1.55 | 1.55 | 1.44 | 1.52 | 1.51 | 1.48 | 1.55 | 1.53 |
