Table 1.
Biological flatness within SOBP of proton beam
| Irradiated condition | Irradiation position | Depth in water (mm) | α (Gy−1) | β (Gy−2) | R2 | D10 (Gy) | RBEplateau | Irradiation position | OER |
|---|---|---|---|---|---|---|---|---|---|
| normoxic | A | 22 | 0.19 ± 0.02 | 0.059 ± 0.001 | 1.00 | 4.81 ± 0.16 | NA | A | 2.84 ± 0.33 |
| B | 74 | 0.17 ± 0.01 | 0.066 ± 0.003 | 1.00 | 4.79 ± 0.06 | 1.00 ± 0.03 | B | 2.60 ± 0.03 | |
| C | 100 | 0.15 ± 0.01 | 0.067 ± 0.005 | 0.99 | 4.88 ± 0.22 | 0.99 ± 0.08 | C | 2.63 ± 0.20 | |
| D | 126 | 0.24 ± 0.12 | 0.064 ± 0.018 | 0.99 | 4.40 ± 0.23 | 1.09 ± 0.09 | D | 2.76 ± 0.31 | |
| hypoxic | A | 22 | 0.09 ± 0.00 | 0.0059 ± 0.0019 | 0.98 | 13.64 ± 1.20 | NA | ||
| B | 74 | 0.11 ± 0.00 | 0.0063 ± 0.0004 | 0.99 | 12.45 ± 0.19 | 1.10 ± 0.09 | |||
| C | 100 | 0.08 ± 0.02 | 0.0076 ± 0.0007 | 0.98 | 12.83 ± 0.39 | 1.06 ± 0.12 | |||
| D | 126 | 0.10 ± 0.03 | 0.0076 ± 0.0011 | 0.96 | 12.13 ± 0.89 | 1.12 ± 0.16 |
SOBP = spread-out Bragg peak, D10 = 10% survival, R2 = coefficient of determination, RBEplateau = relative biological effectiveness to the plateau region, OER = oxygen enhancement ratio, NA = not available. Data represents mean ± standard deviation.