Table 1 The optimization objectives used in the study
| Structure | Objective | Weighting factor |
|---|---|---|
| GTV | Min dose > 58 | 3000 |
| PTV | Min dose > 57 | 3000 |
| Max dose < 63 | ||
| Left lens | Max dose < 5 | 1 |
| Right lens | Max dose < 5 | 1 |
| Left opticus | Max dose < 5 | 1 |
| Right opticus | Max dose < 5 | 1 |
| Chiasma | Max dose < 50 | 1 |
| Brain stem | Max dose < 60 | 1 |
| Pituritary gland | Max dose < 40 | 1 |
| External | Surrounding dose falloff: 60 to 30 Gy in 10 mm | 1000 |