| VOIs/Dose Metrics (Gy) | Mean ± ∆ without perturbations | Mean ± ∆ with perturbations | ||
| PBS | VMAT | PBS | VMAT | |
| PTV54 (D95%) | 54.4 ± 0.4 | 54.1 ± 0.4 | 53.1 ± 1.1 | 51.7 ± 0.8 |
| PTV60 (D95%) | 60.1 ± 0.3 | 59.9 ± 0.3 | 58.6 ± 1.0 | 57.7 ± 1.2 |
| CTV54 (D98%) | 54.3 ± 0.4 | 54.9 ± 0.6 | 53.3 ± 1.1 | 53.9 ± 0.9 |
| CTV60 (D98%) | 60.3 ± 0.3 | 60.6 ± 0.4 | 59.3 ± 0.9 | 59.7 ± 1.0 |
| Brainstem (D.max) | 35.7 ± 7.2 | 36.0 ± 4.9 | 35.2 ± 8.4 | 36.2 ± 5.1 |
| Cord (D.max) | 40.3 ± 4.0 | 39.8 ± 3.7 | 41.8 ± 3.6 | 41.7 ± 3.9 |
| Oral cavity (D.max) | 3.7 ± 2.3 | 18.6 ± 3.1 | 3.4 ± 2.4 | 18.7 ± 3.6 |
| Submandibular (D.mean) | 33.3 ± 5.7 | 32.2 ± 7.9 | 33.6 ± 8.1 | 32.8 ± 8.5 |
| Contralatral Parotid (D.mean) | 15.4 ± 3.5 | 19.5 ± 2.7 | 15.5 ± 4.6 | 19.7 ± 3.6 |
| Ipsilateral Parotid (D.mean) | 26.8 ± 5.5 | 26.8 ± 4.7 | 25.9 ± 6.2 | 27.2 ± 6.0 |
| Larynx (D.mean) | 27.2 ± 2.7 | 31.7 ± 3.9 | 27.7 ± 3.1 | 32.3 ± 3.7 |