Table 2.
Treatment plan comparison cancer for hypopharynx/larynx
| Structure | Parameter | DVO | Dual Arc | Single Arc | IMRT |
|---|---|---|---|---|---|
| PTV | D50% | Uniform | 60.0 Gy | 60.5 Gy | 59.7 Gy |
| H | Dose | 7.0 | 9.4 | 8.0 | |
| V95% | 60 Gy | 97.8% | 95.4% | 95.7% | |
| Normal Tissue | D1% | ≤ 60 Gy | 58.4 Gy | 58.1 Gy | 57.8 Gy |
| D20% | ≤ 21 Gy | 20.1 Gy | 20.4 Gy | 21.5 Gy | |
| D60% | ≤ 4 Gy | 1.9 Gy | 1.9 Gy | 2.0 Gy | |
| Left Parotid | D50% | ≤ 26 Gy | 23.7 Gy | 23.1 Gy | 29.4 Gy |
| Right Parotid | D50% | ≤ 26 Gy | 20.6 Gy | 23.3 Gy | 26.4 Gy |
| Spinal Cord | D1 ccm | ≤ 39 Gy | 36.9 Gy | 39.8 Gy | 37.6 Gy |
| Brain Stem | D1 ccm | ≤ 43 Gy | 34.4 Gy | 41.5 Gy | 36.9 Gy |
| Left Joint* | D50% | - | 2.6 Gy | 2.7 Gy | 2.9 Gy |
| Right Joint* | D50% | - | 2.3 Gy | 2.2 Gy | 2.5 Gy |
| Monitor Units | MU/2.0 Gy | - | 715 | 552 | 799 |
| Time | Calculation | - | 33:10 min | 16:30 min | 4:52 min |
| Delivery | - | 5:00 min | 2:08 min | 14:15 min | |
*temporomandibular joint
DX% and D1 ccm are the doses delivered to X% of the volume and 1 cm3 respectively, V95% the volume receiving 95% of the prescription dose in%, Homogeneity H = (D5% - D95%)/Daverage.