Background
Methods
Sampling of VMAT plans
Fluence generation with edge-enhancement
Calculation of textural features
Quantification of plan delivery accuracy of VMAT
Correlation analysis
Results
Values of textural features
d
= 1
|
d
= 5
|
d
= 10
| |||||||
---|---|---|---|---|---|---|---|---|---|
Prostate
|
H&N
|
p
|
Prostate
|
H&N
|
p
|
Prostate
|
H&N
|
p
| |
ASM (×10−3) | 1.433 ± 0.170 | 0.842 ± 0.264 | <0.001 | 2.183 ± 0.497 | 0.837 ± 0.270 | <0.001 | 2.972 ± 0.650 | 0.989 ± 0.439 | <0.001 |
IDM | 0.236 ± 0.021 | 0.271 ± 0.027 | <0.001 | 0.115 ± 0.013 | 0.167 ± 0.020 | <0.001 | 0.082 ± 0.011 | 0.126 ± 0.015 | <0.001 |
Contrast | 264.73 ± 70.21 | 113.52 ± 51.79 | <0.001 | 960.75 ± 236.74 | 341.90 ± 152.29 | <0.001 | 1737.04 ± 484.32 | 537.56 ± 239.04 | <0.001 |
Variance | 45.48 ± 4.60 | 37.48 ± 7.74 | 0.001 | 46.41 ± 4.49 | 38.59 ± 8.08 | 0.001 | 46.32 ± 4.64 | 39.06 ± 8.10 | 0.002 |
Correlation | 0.874 ± 0.021 | 0.921 ± 0.017 | <0.001 | 0.583 ± 0.050 | 0.791 ± 0.035 | <0.001 | 0.308 ± 0.132 | 0.686 ± 0.059 | <0.001 |
Entropy | 2.971 ± 0.056 | 3.243 ± 0.118 | <0.001 | 2.875 ± 0.071 | 3.308 ± 0.124 | <0.001 | 2.730 ± 0.092 | 3.287 ± 0.151 | <0.001 |
Correlations between textural features and gamma passing rates
2%/2 mm
|
1%/2 mm
|
2%/1 mm
| |||||
---|---|---|---|---|---|---|---|
d
|
r
s
|
p
|
r
s
|
p
|
r
s
|
p
| |
ASM | 1 | 0.373 | 0.018 | 0.623 | <0.001 | 0.174 | 0.282 |
5 | 0.400 | 0.011 | 0.569 | <0.001 | 0.133 | 0.415 | |
10 | 0.381 | 0.015 | 0.571 | <0.001 | 0.187 | 0.249 | |
IDM | 1 | −0.610 | <0.001 | −0.690 | <0.001 | −0.503 | 0.001 |
5 | −0.582 | <0.001 | −0.713 | <0.001 | −0.417 | 0.007 | |
10 | −0.540 | <0.001 | −0.668 | <0.001 | −0.362 | 0.022 | |
Contrast | 1 | 0.546 | <0.001 | 0.744 | <0.001 | 0.487 | 0.001 |
5 | 0.570 | <0.001 | 0.725 | <0.001 | 0.450 | 0.004 | |
10 | 0.554 | <0.001 | 0.740 | <0.001 | 0.402 | 0.010 | |
Variance | 1 | 0.486 | 0.001 | 0.623 | <0.001 | 0.485 | 0.002 |
5 | 0.507 | 0.001 | 0.630 | <0.001 | 0.490 | 0.001 | |
10 | 0.486 | 0.001 | 0.587 | <0.001 | 0.530 | <0.001 | |
Correlation | 1 | −0.390 | 0.013 | −0.648 | <0.001 | −0.279 | 0.082 |
5 | −0.486 | 0.001 | −0.678 | <0.001 | −0.247 | 0.125 | |
10 | −0.374 | 0.017 | −0.633 | <0.001 | −0.093 | 0.569 | |
Entropy | 1 | −0.303 | 0.057 | −0.581 | <0.001 | −0.210 | 0.194 |
5 | −0.363 | 0.021 | −0.594 | <0.001 | −0.201 | 0.213 | |
10 | −0.312 | 0.050 | −0.597 | <0.001 | −0.200 | 0.216 |
2%/2 mm
|
1%/2 mm
|
2%/1 mm
| |||||
---|---|---|---|---|---|---|---|
d
|
r
s
|
p
|
r
s
|
p
|
r
s
|
p
| |
ASM | 1 | 0.522 | 0.001 | 0.603 | <0.001 | 0.469 | 0.002 |
5 | 0.421 | 0.007 | 0.496 | 0.001 | 0.356 | 0.024 | |
10 | 0.389 | 0.013 | 0.489 | 0.001 | 0.334 | 0.035 | |
IDM | 1 | −0.504 | 0.001 | −0.605 | <0.001 | −0.451 | 0.003 |
5 | −0.528 | <0.001 | −0.571 | <0.001 | −0.494 | 0.001 | |
10 | −0.462 | 0.003 | −0.528 | <0.001 | −0.402 | 0.010 | |
Contrast | 1 | 0.588 | <0.001 | 0.640 | <0.001 | 0.644 | <0.001 |
5 | 0.593 | <0.001 | 0.629 | <0.001 | 0.613 | <0.001 | |
10 | 0.603 | <0.001 | 0.642 | <0.001 | 0.584 | <0.001 | |
Variance | 1 | 0.519 | 0.001 | 0.525 | 0.001 | 0.594 | <0.001 |
5 | 0.538 | <0.001 | 0.538 | <0.001 | 0.599 | <0.001 | |
10 | 0.464 | 0.003 | 0.477 | 0.002 | 0.549 | <0.001 | |
Correlation | 1 | −0.473 | 0.002 | −0.585 | <0.001 | −0.458 | 0.003 |
5 | −0.565 | <0.001 | −0.633 | <0.001 | −0.492 | 0.001 | |
10 | −0.561 | <0.001 | −0.605 | <0.001 | −0.430 | 0.006 | |
Entropy | 1 | −0.467 | 0.002 | −0.527 | <0.001 | −0.470 | 0.002 |
5 | −0.447 | 0.004 | −0.529 | <0.001 | −0.437 | 0.005 | |
10 | −0.443 | 0.004 | −0.534 | <0.001 | −0.418 | 0.007 |
Correlations between textural features and MLC positional errors
MLC error
|
Gantry angle error
|
MU error
| |||||
---|---|---|---|---|---|---|---|
d
|
r
s
|
p
|
r
s
|
p
|
r
s
|
p
| |
ASM | 1 | −0.747 | <0.001 | 0.445 | 0.004 | 0.108 | 0.506 |
5 | −0.749 | <0.001 | 0.499 | 0.001 | 0.165 | 0.309 | |
10 | −0.785 | <0.001 | 0.600 | <0.001 | 0.106 | 0.513 | |
IDM | 1 | 0.604 | <0.001 | −0.444 | 0.004 | −0.243 | 0.131 |
5 | 0.821 | <0.001 | −0.705 | <0.001 | −0.217 | 0.179 | |
10 | 0.787 | < 0.001 | −0.716 | < 0.001 | −0.206 | 0.203 | |
Contrast | 1 | −0.853 | < 0.001 | 0.655 | < 0.001 | 0.145 | 0.372 |
5 | −0.843 | < 0.001 | 0.643 | < 0.001 | 0.160 | 0.323 | |
10 | −0.825 | < 0.001 | 0.636 | < 0.001 | 0.217 | 0.179 | |
Variance | 1 | −0.699 | < 0.001 | 0.526 | < 0.001 | 0.110 | 0.501 |
5 | −0.690 | < 0.001 | 0.510 | 0.001 | 0.090 | 0.579 | |
10 | −0.648 | < 0.001 | 0.507 | 0.001 | 0.040 | 0.808 | |
Correlation | 1 | 0.766 | < 0.001 | −0.510 | 0.001 | −0.050 | 0.761 |
5 | 0.758 | < 0.001 | −0.540 | < 0.001 | −0.132 | 0.416 | |
10 | 0.728 | < 0.001 | −0.533 | < 0.001 | −0.157 | 0.332 | |
Entropy | 1 | 0.820 | < 0.001 | −0.516 | 0.001 | −0.095 | 0.559 |
5 | 0.823 | < 0.001 | −0.538 | < 0.001 | −0.169 | 0.297 | |
10 | 0.841 | < 0.001 | −0.592 | < 0.001 | −0.117 | 0.474 |
Correlations between textural features and dose-volumetric parameters
Contrast
|
Correlation
| |||||||
---|---|---|---|---|---|---|---|---|
d
= 1
|
d
= 10
|
d
= 1
|
d
= 10
| |||||
d
= 1
|
d
= 10
|
d
= 1
|
d
= 10
| |||||
Dose-volumetric parameter |
r
s
|
p
|
r
s
|
p
|
r
s
|
p
|
r
s
|
p
|
D20% of rectal wall | - | - | - | - | 0.485 | 0.030 | - | - |
Mean dose to rectal wall | −0.493 | 0.027 | −0.473 | 0.035 | 0.446 | 0.048 | - | - |
Mean dose to bladder | −0.456 | 0.043 | - | - | - | - | - | - |
D50% of femoral heads | - | - | - | - | - | - | 0.448 | 0.047 |
d
= 1
|
d
= 5
|
d
= 10
| ||||
---|---|---|---|---|---|---|
r
s
|
p
|
r
s
|
p
|
r
s
|
p
| |
ASM | ||||||
D5% of target 2 | - | - | 0.501 | 0.026 | - | - |
Mean dose to target 2 | 0.532 | 0.016 | 0.565 | 0.009 | - | - |
D95% of target 3 | - | - | 0.641 | 0.003 | - | - |
D5% of target 3 | 0.558 | 0.013 | 0.635 | 0.003 | - | - |
Mean dose to target 3 | 0.489 | 0.034 | 0.635 | 0.003 | - | - |
IDM | ||||||
D5% of target 1 | - | - | 0.511 | 0.021 | 0.478 | 0.033 |
Mean dose to target 1 | - | - | 0.562 | 0.010 | 0.520 | 0.019 |
D95% of target 2 | - | - | 0.490 | 0.028 | - | - |
Minimum dose to target 2 | 0.447 | 0.048 | - | - | - | - |
Mean dose to target 2 | 0.501 | 0.024 | 0.593 | 0.006 | 0.548 | 0.012 |
D5% of target 3 | - | - | 0.512 | 0.025 | - | - |
Mean dose to right parotid gland | 0.540 | 0.014 | 0.619 | 0.004 | - | - |
Mean dose to left parotid gland | - | - | 0.506 | 0.023 | - | - |
Maximum dose to right optic nerve | 0.498 | 0.025 | 0.517 | 0.020 | - | - |
Contrast | ||||||
D5% of target 1 | - | - | −0.454 | 0.044 | −0.502 | 0.024 |
Mean dose to target 1 | −0.486 | 0.030 | −0.539 | 0.014 | −0.488 | 0.029 |
D95% of target 2 | −0.494 | 0.027 | −0.651 | 0.002 | - | - |
D5% of target 2 | −0.534 | 0.017 | −0.618 | 0.004 | −0.477 | 0.035 |
Minimum dose to target 2 | −0.478 | 0.033 | - | - | - | - |
Mean dose to target 2 | −0.626 | 0.003 | −0.704 | 0.001 | −0.521 | 0.018 |
D95% of target 3 | - | - | −0.508 | 0.026 | - | - |
D5% of target 3 | −0.576 | 0.010 | −0.635 | 0.003 | - | - |
Mean dose to target 3 | −0.484 | 0.036 | −0.493 | 0.032 | - | - |
Mean dose to right parotid gland | −0.595 | 0.006 | −0.516 | 0.020 | - | - |
Maximum dose to right optic nerve | −0.631 | 0.003 | −0.477 | 0.033 | - | - |
Variance | ||||||
D95% of target 1 | −0.553 | 0.012 | −0.558 | 0.011 | −0.589 | 0.006 |
D5% of target 1 | −0.693 | 0.001 | −0.689 | 0.001 | −0.688 | 0.001 |
Mean dose to target 1 | −0.705 | 0.001 | −0.708 | < 0.001 | −0.727 | < 0.001 |
D95% of target 2 | −0.630 | 0.003 | −0.617 | 0.004 | −0.626 | 0.003 |
D5% of target 2 | −0.668 | 0.002 | −0.672 | 0.002 | −0.645 | 0.003 |
Mean dose to target 2 | −0.734 | < 0.001 | −0.733 | < 0.001 | −0.734 | < 0.001 |
D95% of target 3 | −0.553 | 0.014 | −0.548 | 0.015 | −0.519 | 0.023 |
D5% of target 3 | −0.665 | 0.002 | −0.670 | 0.002 | −0.691 | 0.001 |
Maximum dose to target 3 | −0.511 | 0.025 | −0.490 | 0.033 | −0.497 | 0.030 |
Mean dose to target 3 | −0.487 | 0.035 | −0.502 | 0.029 | −0.519 | 0.023 |
Mean dose to right parotid gland | −0.705 | 0.001 | −0.675 | 0.001 | −0.709 | < 0.001 |
Mean dose to left parotid gland | −0.479 | 0.033 | −0.444 | 0.050 | −0.458 | 0.042 |
Maximum dose to right optic nerve | −0.568 | 0.009 | −0.560 | 0.010 | −0.560 | 0.010 |
Correlation | ||||||
D5% of target 1 | −0.589 | 0.006 | −0.546 | 0.013 | - | - |
Maximum dose to target 1 | - | - | −0.490 | 0.028 | - | - |
Entropy | ||||||
D5% of target 1 | - | - | −0.487 | 0.029 | - | - |
Mean dose to target 1 | - | - | −0.466 | 0.038 | - | - |
D5% of target 2 | - | - | −0.519 | 0.021 | −0.451 | 0.047 |
Mean dose to target 2 | −0.465 | 0.039 | −0.537 | 0.015 | - | - |
D95% of target 3 | −0.522 | 0.022 | −0.584 | 0.009 | −0.497 | 0.030 |
D5% of target 3 | −0.598 | 0.007 | −0.656 | 0.002 | −0.543 | 0.016 |
Mean dose to target 3 | −0.487 | 0.035 | −0.552 | 0.014 | - | - |