Table 2.
Dosimetric comparison of OARs for 9F-IMRT, 2ARC-VMAT, and Hybrid IMRT/VMAT plans.
| 9F-IMRT | 2ARC-VMAT | Hybrid | Pairwise comparison | |||
|---|---|---|---|---|---|---|
| p α | p β | p γ | ||||
| Spinal cord | ||||||
| D max (0.03 cc) (Gy) | 41.3 ± 1.9 | 42.3 ± 3.1 | 41.7 ± 2.6 | 0.44 | 1.00 | 0.61 |
| Brainstem | ||||||
| D max (Gy) | 47.7 ± 3.3 | 48.1 ± 3.5 | 47.6 ± 3.1 | 1.00 | 1.00 | 1.00 |
| Optical nerve | ||||||
| D max (Gy) | 34.7 ± 18.3 | 37.8 ± 19.3 | 37.8 ± 17.7 | 0.58 | 0.33 | 1.00 |
| Optic chiasm | ||||||
| D max (Gy) | 40.2 ± 15.5 | 40.8 ± 17.8 | 42.3 ± 16.3 | 1.00 | 0.98 | 0.35 |
| TMJ | ||||||
| D 2% (Gy) | 56.6 ± 7.1 | 53.9 ± 9.1 | 53.5 ± 8.0 | 0.24 | 0.11 | 1.00 |
| Mean (Gy) | 42.9 ± 7.1 | 39.3 ± 7.7 | 37.4 ± 7.7 | 0.02 | 0.00 | 0.34 |
| Mandible | ||||||
| D 2% (Gy) | 67.2 ± 2.1 | 64.7 ± 2.6 | 63.7 ± 1.7 | 0.00 | 0.00 | 0.06 |
| Mean (Gy) | 52.4 ± 2.1 | 49.0 ± 1.3 | 50.2 ± 1.8 | 0.00 | 0.03 | 0.04 |
| Temporal lobe | ||||||
| D 2% (Gy) | 54.2 ± 7.9 | 50.8 ± 10.2 | 50.0 ± 8.3 | 0.23 | 0.09 | 0.92 |
| Mean (Gy) | 24.6 ± 8.3 | 21.4 ± 6.9 | 21.8 ± 6.6 | 0.00 | 0.01 | 0.31 |
| Parotid R | ||||||
| Mean (Gy) | 31.2 ± 1.9 | 29.5 ± 2.4 | 30.4 ± 2.8 | 1.14 | 1.00 | 0.04 |
| V 30 | 33.6 ± 9.7 | 35.7 ± 7.7 | 34.7 ± 9.7 | 1.00 | 1.00 | 1.00 |
| Parotid L | ||||||
| Mean (Gy) | 31.7 ± 2.1 | 30.1 ± 3.1 | 31.0 ± 4.3 | 0.20 | 1.00 | 0.28 |
| V 30 | 37.3 ± 9.6 | 37.1 ± 9.1 | 36.1 ± 14.7 | 1.00 | 1.00 | 1.00 |
| Lens | ||||||
| D max (Gy) | 8.0 ± 3.4 | 6.5 ± 1.9 | 7.4 ± 2.3 | 0.05 | 0.57 | 0.00 |
| Eyes | ||||||
| D max (Gy) | 34.0 ± 4.6 | 27.9 ± 11.4 | 29.1 ± 10.7 | 0.06 | 0.24 | 0.35 |
| Mean (Gy) | 10.5 ± 5.1 | 10.3 ± 5.1 | 10.3 ± 4.7 | 1.00 | 1.00 | 1.00 |
| Unspecified tissue | ||||||
| D 1% (Gy) | 64.7 ± 2.2 | 61.5 ± 2.9 | 61.1 ± 2.4 | 0.00 | 0.00 | 0.79 |
| Mean (Gy) | 17.7 ± 3.9 | 16.5 ± 3.5 | 17.0 ± 3.8 | 0.00 | 0.02 | 0.01 |
TMJ = temporomandibular joint.
p α: 9F-IMRT versus 2ARC-VMAT; p β: 9F-IMRT versus Hybrid; p γ: 2ARC-VMAT versus Hybrid.