Table 5.
Variation in BED values for two patients both treated using with 6 iso-centers to a fixed prescription dose of 13 Gy. The overall treatment time was longer in the second patient. The BED values relate to voxels with the maximum, a median and the minimum value. Dose contributions and dose-rates are given for doses from an iso-center that delivered >1.0 Gy, the range of the other values are given in parentheses. A BED value of ~ 61 was used as the reference again to which all other values were compared.
| Patient 1 (treatment time 61.6 min) | Patient 2 (treatment time 74.9 min) | |||||
| Iso-center protocol | Iso-center dose (Gy) | Dose-rate (Gy/min) | BED | Iso-center dose (Gy) | Dose-rate Gy/min) | BED |
| 1 (Max) | 11.56 (0.46 0.09) |
1.42 - (0.22 0.02) |
70.7 (+15.2%) |
10.50 - (0.68 0.22) |
0.87 - (0.09 0.03) |
64.6 (+6.4%) |
| 2 (Median) | 8.40 2.60 (0.84 – 0.33) |
1.51 0.31 (0.18 – 0.06) |
66.0 (+7.5%) |
8.24 2.25 (0.85 – 0.14) |
0.68 0.34 (0.12 – 0.02) |
60.8 (Reference) |
| 3 (Min) | 7.50 3.40 (0.94 – 0.1) |
0.92 1.63 (0.17 – 0.02) |
61.3 (Reference) |
5.60 3.54 2.50 (1.00 – 0.1) |
0.46 0.48 0.40 (0.4 – 0.16) |
54.6 (-10.1%) |