Background
Methods
Patient selection
Generation of VMAT plans
N
| Energy | Prescription dose | Fraction number | |
---|---|---|---|---|
Trilogy (N = 140) | ||||
H&N | 40 | 6 MV | 67.5 Gy to PTV67.5Gy 54 Gy to PTV54Gy 48 Gy to PTV48Gy | 30 |
Prostate primary | 40 | 15 MV | 50.4 | 28 |
Prostate boost | 40 | 15 MV | 30.6 | 17 |
Liver | 11 | 15 MV | 50 | 25 |
Spine | 9 | 15 MV | 30 | 10 |
TrueBeam STx (N = 100) | ||||
H&N | 20 | 6 MV | 67.5 Gy to PTV67.5Gy 54 Gy to PTV54Gy 48 Gy to PTV48Gy | 30 |
Brain | 20 | 6 MV | 30 | 10 |
Lung SABR | 20 | 6 MV FFF | 60 | 4 |
Spine SABR | 20 | 10 MV FFF | 19 | 1 |
Liver SABR | 20 | 10 MV FFF | 42 | 3 |
Gamma index analysis
Differences in the mechanical parameters between the original VMAT plans and the log files recorded during the VMAT delivery
Modulation complexity score and the differences in the dose-volumetric parameters between the original VMAT plans and the reconstructed VMAT plans with the log files
Correlation analysis
Results
Global gamma passing rates
Local gamma passing rates
Mechanical errors during the VMAT delivery
Modulation complexity score for VMAT
Correlations between the global and local gamma passing rates
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||
---|---|---|---|---|
r
|
p
|
r
|
p
| |
Trilogy (C-series linac) | ||||
3%/3 mm | 0.218 | 0.010 | 0.540 | < 0.001 |
2%/2 mm | 0.621 | < 0.001 | 0.440 | < 0.001 |
2%/1 mm | 0.642 | < 0.001 | 0.339 | < 0.001 |
1%/2 mm | 0.806 | < 0.001 | 0.469 | < 0.001 |
1%/1 mm | 0.770 | < 0.001 | 0.325 | < 0.001 |
TrueBeam STx (SABR + non-SABR) | ||||
3%/3 mm | – | – | 0.271 | 0.006 |
2%/2 mm | 0.451 | < 0.001 | 0.202 | 0.043 |
2%/1 mm | 0.510 | < 0.001 | 0.376 | < 0.001 |
1%/2 mm | 0.860 | < 0.001 | 0.391 | < 0.001 |
1%/1 mm | 0.842 | < 0.001 | 0.383 | < 0.001 |
TrueBeam STx (SABR) | ||||
3%/3 mm | – | – | 0.409 | 0.001 |
2%/2 mm | 0.332 | 0.010 | 0.318 | 0.013 |
2%/1 mm | 0.531 | < 0.001 | 0.519 | < 0.001 |
1%/2 mm | 0.845 | < 0.001 | 0.460 | < 0.001 |
1%/1 mm | 0.851 | < 0.001 | 0.480 | < 0.001 |
TrueBeam STx (non-SABR) | ||||
3%/3 mm | – | – | – | – |
2%/2 mm | 0.434 | 0.005 | – | – |
2%/1 mm | 0.404 | 0.010 | 0.454 | 0.003 |
1%/2 mm | 0.826 | < 0.001 | 0.453 | 0.003 |
1%/1 mm | 0.758 | < 0.001 | 0.506 | 0.001 |
Correlations between the gamma passing rates of the MapCHECK2 and ArcCHECK measurements
Gamma criteria | Global gamma passing rates | Local gamma passing rates | ||
---|---|---|---|---|
r
|
p
|
r
|
p
| |
Trilogy (C-series linac) | ||||
3%/3 mm | – | – | 0.242 | 0.004 |
2%/2 mm | – | – | 0.288 | 0.001 |
2%/1 mm | – | – | 0.260 | 0.002 |
1%/2 mm | – | – | 0.266 | 0.001 |
1%/1 mm | – | – | 0.202 | 0.016 |
TrueBeam STx (SABR + non-SABR) | ||||
3%/3 mm | – | – | 0.365 | < 0.001 |
2%/2 mm | – | – | 0.412 | < 0.001 |
2%/1 mm | – | – | 0.528 | < 0.001 |
1%/2 mm | – | – | 0.468 | < 0.001 |
1%/1 mm | – | – | 0.589 | < 0.001 |
TrueBeam STx (SABR) | ||||
3%/3 mm | – | – | 0.355 | 0.005 |
2%/2 mm | – | – | 0.263 | 0.042 |
2%/1 mm | 0.273 | 0.035 | 0.381 | 0.003 |
1%/2 mm | – | – | 0.275 | 0.033 |
1%/1 mm | – | – | 0.413 | 0.001 |
TrueBeam STx (non-SABR) | ||||
3%/3 mm | – | – | 0.369 | 0.019 |
2%/2 mm | – | – | 0.629 | < 0.001 |
2%/1 mm | – | – | 0.729 | < 0.001 |
1%/2 mm | – | – | 0.637 | < 0.001 |
1%/1 mm | – | – | 0.745 | < 0.001 |
Correlations between the gamma passing rates and the mechanical errors
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||||||
---|---|---|---|---|---|---|---|---|
Global gamma passing rates | Local gamma passing rates | Global gamma passing rates | Local gamma passing rates | |||||
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
| |
Trilogy (C-series linac) | ||||||||
3%/3 mm | 0.213 | 0.011 | − 0.447 | < 0.001 | – | – | – | – |
2%/2 mm | – | – | − 0.183 | 0.031 | 0.307 | < 0.001 | −0.355 | < 0.001 |
2%/1 mm | – | – | 0.190 | 0.025 | 0.536 | < 0.001 | − 0.211 | 0.013 |
1%/2 mm | − 0.334 | < 0.001 | – | – | 0.305 | < 0.001 | − 0.503 | < 0.001 |
1%/1 mm | – | – | – | – | 0.546 | < 0.001 | −0.374 | < 0.001 |
TrueBeam STx (SABR + non-SABR) | ||||||||
3%/3 mm | – | – | −0.339 | 0.001 | – | – | −0.382 | < 0.001 |
2%/2 mm | −0.358 | < 0.001 | −0.478 | < 0.001 | 0.211 | 0.035 | −0.369 | < 0.001 |
2%/1 mm | −0.328 | 0.001 | −0.394 | < 0.001 | 0.458 | < 0.001 | −0.230 | 0.021 |
1%/2 mm | −0.554 | < 0.001 | −0.542 | < 0.001 | – | – | −0.478 | < 0.001 |
1%/1 mm | −0.531 | < 0.001 | −0.502 | < 0.001 | 0.316 | 0.001 | −0.364 | < 0.001 |
TrueBeam STx (non-SABR) | ||||||||
3%/3 mm | – | – | – | – | – | – | −0.699 | < 0.001 |
2%/2 mm | −0.336 | 0.034 | −0.475 | 0.002 | – | – | −0.593 | < 0.001 |
2%/1 mm | −0.507 | 0.001 | −0.470 | 0.002 | 0.463 | 0.003 | – | – |
1%/2 mm | −0.577 | < 0.001 | −0.584 | < 0.001 | – | – | − 0.619 | < 0.001 |
1%/1 mm | − 0.740 | < 0.001 | − 0.622 | < 0.001 | 0.348 | 0.028 | −0.365 | 0.021 |
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||||||
---|---|---|---|---|---|---|---|---|
Global gamma passing rates | Local gamma passing rates | Global gamma passing rates | Local gamma passing rates | |||||
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
| |
TrueBeam STx (SABR + non-SABR) | ||||||||
2%/2 mm | – | – | – | – | − 0.258 | 0.010 | – | – |
1%/2 mm | – | – | – | – | − 0.242 | 0.015 | – | – |
TrueBeam STx (SABR) | ||||||||
2%/2 mm | – | – | – | – | − 0.398 | 0.002 | – | – |
1%/2 mm | – | – | – | – | − 0.405 | 0.001 | – | – |
1%/1 mm | – | – | – | – | − 0.257 | 0.048 | – | – |
TrueBeam STx (non-SABR) | ||||||||
2%/1 mm | – | – | – | – | 0.347 | 0.028 | – | – |
1%/1 mm | – | – | – | – | 0.333 | 0.035 | – | – |
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||||||
---|---|---|---|---|---|---|---|---|
Global gamma passing rates | Local gamma passing rates | Global gamma passing rates | Local gamma passing rates | |||||
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
| |
Trilogy (C-series linac) | ||||||||
3%/3 mm | – | – | − 0.304 | < 0.001 | – | – | − 0.251 | 0.003 |
2%/2 mm | −0.191 | 0.024 | −0.183 | 0.030 | – | – | −0.312 | < 0.001 |
2%/1 mm | −0.238 | 0.005 | – | – | – | – | −0.323 | < 0.001 |
1%/2 mm | −0.211 | 0.012 | – | – | – | – | −0.305 | < 0.001 |
1%/1 mm | −0.216 | 0.010 | – | – | – | – | −0.330 | < 0.001 |
TrueBeam STx (SABR + non-SABR) | ||||||||
3%/3 mm | – | – | – | – | −0.270 | 0.007 | – | – |
2%/2 mm | 0.236 | 0.018 | – | – | −0.317 | 0.001 | – | – |
2%/1 mm | – | – | – | – | − 0.336 | 0.001 | – | – |
1%/2 mm | 0.243 | 0.015 | – | – | – | – | – | – |
TrueBeam STx (SABR) | ||||||||
3%/3 mm | – | – | −0.546 | < 0.001 | – | – | − 0.398 | 0.002 |
2%/2 mm | – | – | − 0.456 | < 0.001 | – | – | − 0.425 | 0.001 |
2%/1 mm | −0.452 | < 0.001 | − 0.581 | < 0.001 | – | – | − 0.519 | < 0.001 |
1%/2 mm | − 0.491 | < 0.001 | − 0.441 | < 0.001 | – | – | − 0.422 | 0.001 |
1%/1 mm | − 0.625 | < 0.001 | − 0.583 | < 0.001 | – | – | − 0.496 | < 0.001 |
TrueBeam STx (non-SABR) | ||||||||
1%/2 mm | 0.343 | 0.030 | 0.323 | 0.042 | – | – | – | – |
1%/1 mm | 0.369 | 0.019 | – | – | – | – | – | – |
Correlations between the gamma passing rates and the MCSv
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||||||
---|---|---|---|---|---|---|---|---|
Global gamma passing rates | Local gamma passing rates | Global gamma passing rates | Local gamma passing rates | |||||
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
| |
Trilogy (C-series linac) | ||||||||
3%/3 mm | 0.193 | 0.023 | 0.448 | < 0.001 | – | – | 0.340 | < 0.001 |
2%/2 mm | 0.268 | 0.001 | 0.392 | < 0.001 | – | – | 0.378 | < 0.001 |
2%/1 mm | 0.433 | < 0.001 | 0.352 | < 0.001 | – | – | 0.529 | < 0.001 |
1%/2 mm | 0.311 | < 0.001 | 0.238 | 0.005 | – | – | 0.282 | 0.001 |
1%/1 mm | 0.482 | < 0.001 | 0.268 | 0.001 | – | – | 0.453 | < 0.001 |
TrueBeam STx | ||||||||
3%/3 mm | – | – | – | – | −0.243 | 0.015 | – | – |
2%/1 mm | – | – | – | – | − 0.196 | 0.050 | – | – |
Correlations of the gamma passing rates to the differences in the dose-volumetric parameters between the original plans and the plans reconstructed with log files
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||||||
---|---|---|---|---|---|---|---|---|
Global gamma passing rates | Local gamma passing rates | Global gamma passing rates | Local gamma passing rates | |||||
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
| |
TrueBeam STx (SABR + non-SABR) | ||||||||
3%/3 mm | – | – | – | – | – | – | − 0.225 | 0.025 |
2%/2 mm | – | – | − 0.264 | 0.008 | – | – | − 0.240 | 0.016 |
2%/1 mm | – | – | − 0.238 | 0.017 | – | – | − 0.274 | 0.006 |
1%/2 mm | −0.283 | 0.004 | −0.294 | 0.003 | – | – | −0.279 | 0.005 |
1%/1 mm | −0.333 | 0.001 | −0.313 | 0.001 | – | – | −0.318 | 0.001 |
TrueBeam STx (non-SABR) | ||||||||
2%/2 mm | – | – | −0.326 | 0.040 | – | – | – | – |
2%/1 mm | – | – | −0.340 | 0.032 | – | – | – | – |
1%/2 mm | – | – | −0.323 | 0.042 | – | – | – | – |
1%/1 mm | −0.421 | 0.007 | −0.436 | 0.005 | – | – | – | – |
Gamma criteria | MapCHECK2 measurements | ArcCHECK measurements | ||||||
---|---|---|---|---|---|---|---|---|
Global gamma passing rates | Local gamma passing rates | Global gamma passing rates | Local gamma passing rates | |||||
r
|
p
|
r
|
p
|
r
|
p
|
r
|
p
| |
Trilogy (C-series linac) | ||||||||
2%/1 mm | – | – | − 0.166 | 0.050 | – | – | – | – |
1%/1 mm | – | – | −0.187 | 0.027 | −0.185 | 0.029 | – | – |
TrueBeam STx (SABR + non-SABR) | ||||||||
3%/3 mm | – | – | – | – | – | – | −0.293 | 0.003 |
2%/2 mm | – | – | – | – | – | – | −0.327 | 0.001 |
2%/1 mm | −0.253 | 0.011 | – | – | – | – | −0.328 | 0.001 |
1%/2 mm | – | – | – | – | – | – | −0.332 | 0.001 |
1%/1 mm | −0.254 | 0.011 | – | – | – | – | −0.326 | 0.001 |
TrueBeam STx (SABR) | ||||||||
2%/1 mm | – | – | – | – | – | – | −0.293 | 0.023 |
1%/2 mm | – | – | 0.264 | 0.042 | – | – | – | – |
TrueBeam STx (non-SABR) | ||||||||
3%/3 mm | – | – | – | – | – | – | −0.351 | 0.027 |
2%/2 mm | – | – | – | – | – | – | −0.351 | 0.027 |
1%/2 mm | – | – | – | – | – | – | −0.335 | 0.035 |