TABLE 4.
Calculated dose–volume metrics across plan types, scan protocols, and reconstructions for the anthropomorphic head phantom.
| Head and Neck IMRT | |||||
|---|---|---|---|---|---|
| Treatment planning metrics | CT‐sim 120 kV | Head FDK 100 kV | Head iCBCT 100 kV | Head* FDK 125 kV | Head* iCBCT 125 kV |
| PTV_High D98% (Gy) | 69.5 | 69.7 | 69.8 | 69.6 | 69.8 |
| PTV_High D50% (Gy) | 72.2 | 72.4 | 72.4 | 72.3 | 72.3 |
| PTV_High D2% (Gy) | 74.6 | 74.8 | 74.7 | 74.6 | 74.7 |
| PTV_High D0.03cc (Gy) | 76.1 | 76.0 | 76.0 | 75.9 | 75.9 |
| PTV_Mid D98% (Gy) | 61.8 | 62.2 | 62.3 | 62.2 | 62.3 |
| PTV_Mid D50% (Gy) | 71.3 | 71.4 | 71.5 | 71.3 | 71.4 |
| PTV_Mid D2% (Gy) | 74.3 | 74.5 | 74.5 | 74.3 | 74.4 |
| PTV_Low D98% (Gy) | 54.3 | 54.5 | 54.5 | 54.5 | 54.5 |
| PTV_Low D50% (Gy) | 57.8 | 57.9 | 57.9 | 57.8 | 57.9 |
| PTV_Low D2% (Gy) | 60.4 | 60.5 | 60.5 | 60.5 | 60.5 |
| Parotid_L Dmean (Gy) | 25.8 | 26.0 | 26.0 | 26.0 | 26.0 |
| Parotid_R Dmean (Gy) | 29.8 | 29.6 | 29.8 | 29.8 | 29.9 |
| Cord D0.03cc (Gy) | 41.0 | 41.3 | 41.2 | 41.1 | 41.2 |
| Hippocampal avoidance IMRT | |||||
| PTV D98% (Gy) | 26.2 | 26.2 | 26.2 | 26.2 | 26.2 |
| PTV D50% (Gy) | 32.6 | 32.7 | 32.7 | 32.7 | 32.7 |
| PTV D2% (Gy) | 35.8 | 35.8 | 35.8 | 35.8 | 35.8 |
| PTV D0.03cc (Gy) | 37.9 | 38.1 | 38.0 | 38.0 | 38.0 |
| Hippocampus D0.03cc (Gy) | 16.2 | 16.1 | 16.1 | 16.1 | 16.2 |
| Brain SRS | |||||
| PTV D98% (Gy) | 27.0 | 27.1 | 27.1 | 26.9 | 27.1 |
| PTV D50% (Gy) | 32.5 | 32.7 | 32.6 | 32.6 | 32.5 |
| PTV D2% (Gy) | 35.4 | 35.7 | 35.5 | 35.5 | 35.5 |
| PTV D0.03cc (Gy) | 35.4 | 35.6 | 35.5 | 35.5 | 35.5 |
| Brain‐GTV D15cc (Gy) | 5.8 | 5.9 | 5.9 | 5.9 | 5.9 |
Abbreviations: CBCT, cone beam computed tomography; CT, computed tomography; FDK, Feldkamp–Davis–Kress, IMRT, intensity‐modulated radiotherapy; SRS, stereotactic radiosurgery.