Table 3.
Dose–volume parameters of the organs at risk
| FP | hIMRTa | h3DCRTa | P b | P c | |
|---|---|---|---|---|---|
| Median (range) | |||||
| Lung V20Gya (%) | 4.7 (2.1–9.6) | 4.0 (1.9–8.6) | 5.7 (2.7–10.7) | < 0.0001 | 0.53 |
| Rib max (Gy)d | 74.2 (22.3–82.0) | 61.0 (21.6–78.5) | 61.9 (27.6–65.6) | 0.062 | < 0.01 |
| Skin max (Gy)d | 19.0 (16.7–37.5) | 16.5 (9.4–42.0) | 20.1 (11.0–51.2) | 0.26 | 0.72 |
| Spinal cord max (Gy)e | 9.1 (2.4–12.0) | 8.1 (4.3–9.4) | 10.3 (8.4–16.2) | 0.041 | 1.0 |
| Esophagus max (Gy)e | 13.3(3.9–16.6) | 8.6 (6.4–13.9) | 15.3 (11.1–19.1) | 0.022 | 1.0 |
| Trachea max (Gy)e | 16.7 (16.0–27.7) | 14.1 (11.4–42.6) | 25.5 (17.3–34.7) | 0.091 | 1.0 |
| Heart max (Gy)e | 4.2 (0.4–43.6) | 1.7 (0.3–44.0) | 2.2 (0.4–61.0) | 0.074 | 1.0 |
| Great vessels | |||||
| D10ml Max (Gy)a,e | 21.8 (7.0–37.9) | 17.5 (12.6–32.6) | 25.9 (22.0–45.9) | 0.022 | 1.0 |
ahIMRT = helical-IMRT mode, h3DCRT = helical-3DCRT mode, V20Gy = percentage volume receiving 20 Gy, D10ml = irradiated dose to 10 mL of the volume.
b P Value among three plans.
c P Value between FP and hIMRT plans.
dFor tumors located in peripheral zone (n = 9).
eFor tumors located in central zone (n = 5).