Figure 1
![Illustration of the arc angle for coplanar arc (A), non-coplanar arc (B), maximum jaw position for non-coplanar arc (C). (Slate blue, internal mammary nodes planning target volume [PTVimn])](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/647356174e662f30ba53aacf/j_raon-2021-0045_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251204%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251204T200041Z&X-Amz-Expires=3600&X-Amz-Signature=3fc012266aceea80c3a4380088c6b5e77ae4b15ad95fdc724e83e791758356ae&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 2
![Comparison of transverse (A) and sagittal (B) distribution between coplanar volumetric modulated arc therapy [coVMAT] (left) and non-coplanar volumetric modulated arc therapy (ncVMAT) (right). (Color wash: green, breast planning target volume [PTVbreast]; slate blue, internal mammary nodes planning target volume [PTVimn]; olive, supraclavicular nodes panning target volume [PTVscn]; Contour: red, descending coronary artery [LAD;] brown, heart).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/647356174e662f30ba53aacf/j_raon-2021-0045_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251204%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251204T200041Z&X-Amz-Expires=3600&X-Amz-Signature=c9c198a7b1c09b925746108eb04ab665a46984ac13e60b9d69e4e19b74a1d201&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 3
![Dose-volume histogram of planning target volume (PTV) and selected organs-at-risk (OARs) (Solid line, coplanar volumetric modulated arc therapy [coVMAT]; dashed line, non-coplanar volumetric modulated arc therapy [ncVMAT]).](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/647356174e662f30ba53aacf/j_raon-2021-0045_fig_003.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20251204%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20251204T200041Z&X-Amz-Expires=3600&X-Amz-Signature=3e37b788de27196e462b33b2322d2709a45539facdddaa35b341afcc47ba66c2&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Comparison of dosimetric parameters between coplanar volumetric modulated arc therapy (coVMAT) and non-coplanar volumetric modulated arc therapy (ncVMAT) for heart and lung
| Parameters | coVMAT | ncVMAT | p | |
|---|---|---|---|---|
| Heart | V5 (%) | 61.48 ± 19.63 | 48.70 ± 18.88 | < 0.001 |
| V10 (%) | 35.50 ± 15.05 | 26.64 ± 11.97 | < 0.001 | |
| V20 (%) | 16.70 ± 8.70 | 13.07 ± 6.75 | < 0.001 | |
| V30 (%) | 8.53 ± 5.28 | 6.68 ± 3.75 | 0.001 | |
| Dmean (Gy) | 11.16 ± 3.45 | 9.22 ± 2.98 | < 0.001 | |
| Left lung | V5 (%) | 71.67 ± 12.23 | 59.48 ± 10.51 | < 0.001 |
| V(%) 10 | 47.59 ± 8.06 | 40.48 ± 6.41 | < 0.001 | |
| V20 (%) | 26.43 ± 3.95 | 23.55 ± 3.05 | < 0.001 | |
| Dmean (Gy) | 15.27 ± 2.03 | 13.59 ± 1.76 | < 0.001 | |
| Contralateral lung | V5 (%) | 9.67 ± 5.35 | 6.10 ± 4.19 | < 0.001 |
| V10 (%) | 0.87 ± 0.78 | 0.46 ± 0.50 | 0.003 | |
| Dmean (Gy) | 2.82 ± 0.54 | 2.43 ± 0.49 | < 0.001 |
Comparison of dosimetric parameters between coplanar volumetric modulated arc therapy (coVMAT) and non-coplanar volumetric modulated arc therapy (ncVMAT) for planning target volume (PTV)
| Parameters | coVMAT | ncVMAT | p | |
|---|---|---|---|---|
| PTVall | CI | 0.84 ± 0.04 | 0.86 ± 0.03 | 0.028 |
| HI | 1.10 ± 0.02 | 1.09 ± 0.01 | 0.019 | |
| V55 (%) | 6.32 ± 6.35 | 3.46 ± 3.02 | 0.011 | |
| PTVimn | V45 (%) | 99.85 ± 0.14 | 99.85 ± 0.21 | 0.67 |
| V50 (%) | 95.62 ± 0.39 | 95.67 ± 0.73 | 0.94 | |
| V55 (%) | 4.25 ± 4.53 | 1.08 ± 1.88 | < 0.001 | |
| PTVscn | V(%) 50 | 95.31 ± 0.43 | 95.37 ± 0.61 | 0.681 |
| V55 (%) | 1.46 ± 2.89 | 0.22 ± 0.48 | 0.001 | |
| PTVbreast | V(%) 50 | 95.20 ± 0.52 | 94.98 ± 0.38 | 0.054 |
| V55 (%) | 8.09 ± 8.84 | 4.71 ± 4.19 | 0.028 |
Comparison of dosimetric parameters between coplanar volumetric modulated arc therapy (coVMAT) and non-coplanar volumetric modulated arc therapy (ncVMAT) for other organ-at-risk (OAR)
| Parameters | coVMAT | ncVMAT | p | |
|---|---|---|---|---|
| Contralateral breast | V5 (%) | 9.06 ± 5.22 | 4.98 ± 2.63 | < 0.001 |
| V10 (%) | 1.53 ± 1.60 | 0.23 ± 0.27 | < 0.001 | |
| Dmean (Gy) | 2.62 ± 0.60 | 2.16 ± 0.41 | < 0.001 | |
| LAD | Dmax (Gy) | 48.90 ± 8.19 | 46.03 ± 8.20 | < 0.001 |
| Dmean (Gy) | 27.39 ± 8.20 | 23.25 ± 7.16 | < 0.001 | |
| Left humeral head | V30 (%) | 14.47 ± 16.06 | 13.50 ± 13.26 | 0.845 |
| Dmean (Gy) | 19.96 ± 5.11 | 20.32 ± 5.23 | 0.737 | |
| Esophagus | Dmax (Gy) | 51.61 ± 4.64 | 51.24 ± 3.90 | 0.052 |
| Dmean (Gy) | 31.22 ± 5.92 | 33.33 ± 6.09 | < 0.001 | |
| Left brachial plexus | Dmax (Gy) | 54.32 ± 1.05 | 53.44±0.98 | 0.004 |
| Dmean (Gy) | 49.77 ± 2.79 | 49.36 ± 2.74 | 0.019 | |
| Thyroid | V30 (%) | 45.96 ± 8.83 | 46.10 ± 12.47 | 0.044 |
| Dmax (Gy) | 54.13 ± 0.77 | 53.64 ± 0.86 | 0.009 | |
| Dmean (Gy) | 30.79 ± 3.39 | 29.60 ± 4.71 | 0.015 | |
| Spinal cord | Dmax (Gy) | 26.88 ± 5.53 | 29.38 ± 4.76 | 0.073 |