Table 1. List of planning target volumes and organs at risk.
GTV_OPT: gross tumor volume optimized; PTV: planning target volume; CT: computed tomography; PET: positron emission tomography.
| Target Volumes and Organs at Risk | Definition | Derivation |
| GTV | Gross tumor volume | Visible tumor on CT or PET |
| PTV | Planning target volume | GTV + 0.5 cm |
| PTV-GTV | Planning target volume minus gross tumor volume | PTV - GTV |
| GTV_OPT | Optimized gross tumor volume | PTV_OPT - 0.3 cm |
| PTV_OPT | Optimized planning target volume | PTV - (bronchus small airway + 0.3 cm) - (heart/pericardium + 0.2 cm) |
| Body | - | - |
| Brachial plexus | - | - |
| Bronchus/small airway | - | - |
| Esophagus | - | - |
| Great vessels | - | - |
| Heart/pericardium | - | - |
| Left lung | - | - |
| Lung | - | - |
| Ribs | - | - |
| Right lung | - | - |
| Skin | - | - |
| Spinal cord | - | - |
| Trachea/large bronchus | - | - |