Table 1.
Dose–volume histogram constraints used for volumetric modulated arc therapy.
| Structure | Constraint | |
| Conventional plan | Dose painting plan | |
| PTV54 | V 51.3 Gy ≥98% and V 54 Gy ≤1% | V 51.3 Gy ≥98% and V 54 Gy ≤1% |
| PTV60 | V 95% ≥ 98% and D max ≤110% | V 95% ≥ 98% and D max ≤110% for PTV60 outside of BTVs |
| PTV60b | V 95% ≥ 98% and D max ≤ 60 Gy | V 95% ≥ 98% and D max ≤ 60 Gy |
| Optics_PRV | V 54 Gy ≤1% | V 54 Gy ≤1% |
| Brainstem | D max ≤ 60 Gy | D max ≤ 60 Gy |
| Retina | D max ≤ 45 Gy | D max ≤ 45 Gy |
| Anterior chamber | D max ≤ 10 Gy | D max ≤ 10 Gy |
| BTV62.5 | — | V 59.3 Gy ≥95% |
| BTV65 | — | V 61.8 Gy ≥95% |
| BTV67.5 | — | V 64.1 Gy ≥95% |
| BTV70 | — | V 66.5 Gy ≥95% |
| BTV72.5 | — | V 68.9 Gy ≥95% |
| BTV75 | — | V 71.3 Gy ≥95% |
| BTV77.5 | — | V 73.6 Gy ≥95% and D max ≤ 80 Gy |
Vx is the percentage volume of a structure that received a dose of x or greater.BTV, biological target volumes; D max = maximum dose;PTV, planning target volume.