Background
Methods
Patient selection
Neurocognitive assessments
Neurocognitive Function Test | Domain |
---|---|
Memory | |
WMS-III Word Lists (immediate, delayed recall and recognition) | Verbal memory |
WMS-III Visual Reproduction (immediate, delayed recall and recognition) | Visual memory |
WAIS-III Digit Span | Working memory |
Processing speed | |
WAIS-III Digit Symbol | Psychomotor speed |
WAIS-III Symbol Search Tests | Psychomotor speed |
Executive Functions | |
Wisconsin Card Sorting Test | Cognitive flexibility |
Treatment planning and delivery
Statistical analysis
Results
Neurocognitive outcomes directly related to hippocampus-dependent memory functions
Performance of VMAT plan and DVH results of the hippocampal structure
Bilateral hippocampi | Left hippocampus | Right hippocampus | ||||
---|---|---|---|---|---|---|
Mean (95 % CI) | Median | Mean (95 % CI) | Median | Mean (95 % CI) | Median | |
Volume (c.c.) | 4.99 (4.59–5.40) | 5.18 | 2.41 (2.20–2.62) | 2.41 | 2.58 (2.37–2.79) | 2.71 |
Maximum EQD2 (Gy) | 13.51 (11.85–15.17) | 12.64 | 13.20 (11.50–14.9) | 12.41 | 12.93 (11.64–14.22) | 12.64 |
D20% EQD2 (Gy) | 8.30 (7.81–8.78) | 8.26 | 8.34 (7.86–8.82) | 8.22 | 8.27 (7.78–8.76) | 8.28 |
D40% EQD2 (Gy) | 7.65 (7.19–8.11) | 7.68 | 7.67 (7.22–8.12) | 7.70 | 7.63 (7.16–8.10) | 7.70 |
D50% EQD2 (Gy) | 7.40 (6.96–7.85) | 7.45 | 7.41 (6.97–7.85) | 7.48 | 7.37 (6.92–7.82) | 7.47 |
D80% EQD2 (Gy) | 6.70 (6.32–7.07) | 6.80 | 6.72 (6.35–7.09) | 6.73 | 6.69 (6.30–7.07) | 6.84 |
Minimum EQD2 (Gy) | 5.78 (5.51–6.04) | 5.82 | 5.61 (5.04–6.18) | 5.73 | 5.86 (5.58–6.14) | 5.90 |
Correlation of Hippocampal dosimetry with neurocognitive functions
Dosimetric parameters | Dosimetric cut-off points | NCF Preservation N (%) | No preservation |
p value |
---|---|---|---|---|
Bilateral hippocampi as a composite structure | ||||
Maximum | ≤12.6 Gy | 10(83.3 %) | 2(16.7 %) | 0.004* |
>12.6 Gy | 3(25.0 %) | 9(75.0 %) | ||
D10%
| ≤8.81 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>8.81 Gy | 4(33.3 %) | 8(66.7 %) | ||
D20%
| ≤8.26 Gy | 8(66.7 %) | 4(33.3 %) | 0.219 |
>8.26 Gy | 5(41.7 %) | 7(58.3 %) | ||
D30%
| ≤7.95 Gy | 8(66.7 %) | 4(33.3 %) | 0.219 |
>7.95 Gy | 5(41.7 %) | 7(58.3 %) | ||
D40%
| ≤7.68 Gy | 8(66.7 %) | 4(33.3 %) | 0.219 |
>7.68 Gy | 5(41.7 %) | 7(58.3 %) | ||
D50%
| ≤7.45 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>7.45 Gy | 4(33.3 %) | 8(66.7 %) | ||
D80%
| ≤6.80 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>6.80 Gy | 4(33.3 %) | 8(66.7 %) | ||
D100%
| ≤5.83 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>5.83 Gy | 4(33.3 %) | 8(66.7 %) | ||
Left hippocampus | ||||
Maximum | ≤12.41 Gy | 10(83.3 %) | 2(16.7 %) | 0.004* |
>12.41 Gy | 3(25.0 %) | 9(75.0 %) | ||
D10%
| ≤8.75 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>8.75 Gy | 4(33.3 %) | 8(66.7 %) | ||
D20%
| ≤8.22 Gy | 8(66.7 %) | 4(33.3 %) | 0.219 |
>8.22 Gy | 5(41.7 %) | 7(58.3 %) | ||
D30%
| ≤7.94 Gy | 8(66.7 %) | 4(33.3 %) | 0.219 |
>7.94 Gy | 5(41.7 %) | 7(58.3 %) | ||
D40%
| ≤7.70 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>7.70 Gy | 4(33.3 %) | 8(66.7 %) | ||
D50%
| ≤7.48 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>7.48 Gy | 4(33.3 %) | 8(66.7 %) | ||
D80%
| ≤6.73 Gy | 9(75.0 %) | 3(25.0 %) | 0.041* |
>6.73 Gy | 4(33.3 %) | 8(66.7 %) | ||
D100%
| ≤5.73 Gy | 8(66.7 %) | 4(33.3 %) | 0.219 |
>5.73 Gy | 5(41.7 %) | 7(58.3 %) |
Dosimetry | Dosimetric cut-off points | NCF Preservation N (%) | No preservation |
p value |
---|---|---|---|---|
Bilateral hippocampi as a composite structure | ||||
Maximum | ≤12.6 Gy | 9(75.0 %) | 3(25.0 %) | 0.098 |
>12.6 Gy | 5(41.7 %) | 7(58.3 %) | ||
D10%
| ≤8.81 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>8.81 Gy | 7(58.3 %) | 5(41.7 %) | ||
D20%
| ≤8.26 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>8.26 Gy | 7(58.3 %) | 5(41.7 %) | ||
D30%
| ≤7.95 Gy | 6(50.0 %) | 6(50.0 %) | 0.408 |
>7.95 Gy | 8(66.7 %) | 4(33.3 %) | ||
D40%
| ≤7.68 Gy | 6(50.0)% | 6(50.0 %) | 0.408 |
>7.68 Gy | 8(66.7 %) | 4(33.3 %) | ||
D50%
| ≤7.45 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>7.45 Gy | 7(58.3 %) | 5(41.7 %) | ||
D80%
| ≤6.80 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>6.80 Gy | 7(58.3 %) | 5(41.7 %) | ||
D100%
| ≤5.83 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>5.83 Gy | 7(58.3 %) | 5(41.7 %) | ||
Left hippocampus | ||||
Maximum | ≤12.41 Gy | 10(83.3 %) | 2(16.7 %) | 0.013* |
>12.41Gy | 4(33.3 %) | 8(66.7 %) | ||
D10%
| ≤8.75Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>8.75 Gy | 7(58.3 %) | 5(41.7 %) | ||
D20%
| ≤8.22 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>8.22 Gy | 7(58.3 %) | 5(41.7 %) | ||
D30%
| ≤7.94 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>7.94 Gy | 7(58.3 %) | 5(41.7 %) | ||
D40%
| ≤7.70 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>7.70 Gy | 7(58.3 %) | 5(41.7 %) | ||
D50%
| ≤7.48 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>7.48 Gy | 7(58.3 %) | 5(41.7 %) | ||
D80%
| ≤6.73 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>6.73 Gy | 7(58.3 %) | 5(41.7 %) | ||
D100%
| ≤5.73 Gy | 7(58.3 %) | 5(41.7 %) | 1 |
>5.73 Gy | 7(58.3 %) | 5(41.7 %) |
NCF tests | Dosimetric parameters | Crude OR (p-value) | Adjusted OR | Statistical significance | 95 % CI |
---|---|---|---|---|---|
WLL-IR | |||||
R-hippo mean | 2.232 (p = 0.108) | 2.901 | 0.077 | 0.893–9.424 | |
R-hippo max | 1.026 (p = 0.856) | 1.040 | 0.802 | 0.763–1.419 | |
R-hippo min | 4.380 (p = 0.077) | 5.818 | 0.061 | 0.920–36.805 | |
L-hippo mean | 2.870 (p = 0.060) | 4.080 | 0.0420* | 1.055–15.780 | |
L-hippo max | 1.003 (p = 0.975) | 1.012 | 0.920 | 0.802–1.276 | |
L-hippo min | 7.903 (p = 0.037*) | 14.345 | 0.040* | 1.126–182.689 | |
B-hippo mean | 2.569 (p = 0.076) | 3.510 | 0.052 | 0.989–12.460 | |
B-hippo max | 1.004 (p = 0.974) | 1.011 | 0.930 | 0.797–1.282 | |
B-hippo min | 5.333 (p = 0.070) | 8.147 | 0.060 | 0.917–72.401 | |
WLL-LTDR | |||||
R-hippo mean | 1.114 (p = 0.805) | 1.169 | 0.769 | 0.413–3.313 | |
R-hippo max | 0.894 (p = 0.551) | 0.883 | 0.652 | 0.513–1.519 | |
R-hippo min | 1.203 (p = 0.784) | 1.339 | 0.716 | 0.277–6.481 | |
L-hippo mean | 1.218 (p = 0.665) | 1.366 | 0.581 | 0.452–4.129 | |
L-hippo max | 0.926 (p = 0.596) | 0.973 | 0.864 | 0.711–1.332 | |
L-hippo min | 1.784 (p = 0.352) | 2.249 | 0.322 | 0.453–11.178 | |
B-hippo mean | 1.176 (p = 0.718) | 1.291 | 0.643 | 0.438–3.809 | |
B-hippo max | 0.918 (p = 0.574) | 0.938 | 0.738 | 0.644–1.366 | |
B-hippo min | 1.349 (p = 0.672) | 1.612 | 0.584 | 0.292–8.897 | |
WLL-R | |||||
R-hippo mean | 0.994 (p = 0.990) | 1.262 | 0.699 | 0.389–4.093 | |
R-hippo max | 1.321 (p = 0.183) | 3.091 | 0.147 | 0.671–14.232 | |
R-hippo min | 1.481 (p = 0.616) | 1.966 | 0.430 | 0.367–10.528 | |
L-hippo mean | 1.177 (p = 0.757) | 1.573 | 0.460 | 0.473–5.234 | |
L-hippo max | 1.370 (p = 0.209) | 2.290 | 0.084 | 0.894–5.868 | |
L-hippo min | 1.669 (p = 0.465) | 2.199 | 0.357 | 0.412–11.746 | |
B-hippo mean | 1.089 (p = 0.870) | 1.424 | 0.563 | 0.430–4.718 | |
B-hippo max | 1.309 (p = 0.214) | 2.308 | 0.114 | 0.817–6.521 | |
B-hippo min | 1.632 (p = 0.551) | 2.273 | 0.363 | 0.388–13.305 |