Table 2.
Dosimetric comparisons between IMRT and 3D-CRT
| Parameter | IMRT |
3D-CRT |
P value | ||
|---|---|---|---|---|---|
| Mean | SD | Mean | SD | ||
| Lung | |||||
| V5 Gy | 42.0 | 11.4 | 45.3 | 16.9 | .76 |
| V20 Gy | 21.5 | 7.8 | 26.1 | 10.2 | <.01 |
| Mean dose | 11.9 | 3.9 | 14.9 | 5.0 | <.01 |
| Esophagus | |||||
| V20 Gy | 35.2 | 12.7 | 50.4 | 19.3 | <.01 |
| V45 Gy | 16.0 | 11.2 | 37.5 | 16.5 | <.01 |
| V60 Gy | 6.5 | 8.1 | 21.0 | 15.3 | <.01 |
| Mean dose | 18.3 | 6.7 | 27.8 | 10.1 | <.01 |
| Heart | |||||
| V5 Gy | 28.9 | 28.6 | 33.7 | 26.4 | <.01 |
| V30 Gy | 9.8 | 12.4 | 15.9 | 20.0 | .10 |
| V45 Gy | 4.5 | 6.2 | 9.2 | 13.4 | .08 |
| V60 Gy | 1.0 | 1.43 | 3.2 | 6.3 | .17 |
| Heterogeneity Index | 0.14 | 0.07 | 0.11 | 0.04 | .26 |
| Conformity Index | 0.58 | 0.13 | 0.30 | 0.13 | <.01 |
3D-CRT, 3-dimensional conformal radiation therapy; IMRT, intensity modulated radiation therapy; SD, standard deviation.