Table 3.
Dose to organs at risk. For paired structures, the highest value is listed
| Organs at risk | Conventional planning | Hippocampal blocking | Statistical difference (paired t‑test) | ||
|---|---|---|---|---|---|
| Dose in 12 fractions | EQD2 α/β = 2 | Dose in 12 fractions | EQD2 α/β = 2 | ||
| Hippocampus | |||||
| Dmean ± SD (Gy) | 10.07 ± 0.96 | 7.14 ± 0.49 | 8.79 ± 0.99 | 6.00 ± 0.52 | p < 0.00001 |
| D2% ± SD (Gy) | 14.48 ± 0.38 | 11.61 ± 0.93 | 10.88 ± 0.48 | 7.91 ± 1.99 | p < 0.00001 |
| D98% ± SD (Gy) | 8.49 ± 0.50 | 5.75 ± 0.26 | 7.87 ± 0.28 | 5.23 ± 0.14 | p < 0.00001 |
| D40% ± SD (Gy) | 9.95 ± 0.76 | 7.04 ± 0.39 | 8.58 ± 0.63 | 5.82 ± 0.32 | p < 0.00001 |
| Brainstem | 32.81 ± 0.95 | 38.83 ± 0.49 | 31.87 ± 1.03 | 37.10 ± 0.54 | |
| D2% ± SD (Gy) | p = 0.0014 | ||||
| Optical nerves | 32.30 ± 2.14 | 37.89 ± 1.17 | 31.91 ± 2.48 | 37.17 ± 1.37 | |
| D2% ± SD (Gy) | p = 0.122 | ||||
| Chiasm | 31.66 ± 4.12 | 36.71 ± 2.41 | 30.72 ± 4.20 | 35.02 ± 2.47 | |
| D2% ± SD (Gy) | p < 0.00001 | ||||
| Eyes | 20.47 ± 5.05 | 18.96 ± 2.84 | 17.25 ± 3.83 | 14.82 ± 2.22 | |
| D2% ± SD (Gy) | p = 0.0013 | ||||
| Inner ears | 31.68 ± 1.30 | 36.75 ± 0.69 | 31.81 ± 1.62 | 36.99 ± 0.86 | |
| D2% ± SD (Gy) | p = 0.611 | ||||
| Lenses | 6.09 ± 0.58 | 3.82 ± 0.30 | 6.22 ± 0.89 | 3.92 ± 0.46 | |
| D2% ± SD (Gy) | p = 0.436 | ||||
EQD2 α/β = 2 equivalent dose in 2 Gy fractions, considering an α/β ratio of 2, Dmean mean dose; D2%, near-maximum dose, D98% near-minimum dose, D40% dose applied to 40% of the bilateral hippocampus