Table 2:
Summary of the dose indices on isocenter-shift plan for the lateral and superior-inferior directions
| Original 0 cm | Laterally toward midlinea 0.5 cm | Laterally away from midlinea 0.5 cm | Foota 0.5 cm | Heada 0.5 cm | |||
|---|---|---|---|---|---|---|---|
| CTVevl | Mean (%) | CW | 102.0 | 102.2 | 101.6 | 101.8 | 102.0 |
| FIF | 100.2 | 100.5 | 99.6 | 100.1 | 100.2 | ||
| ISC | 100.3 | 101.1 | 99.7 | 100.5 | 100.4 | ||
| D95 (%) | CW | 97.6 | 97.8 | 97.2 | 97.4 | 97.6 | |
| FIF | 95.8 | 95.4 | 95.7 | 95.5 | 95.8 | ||
| ISC | 97.3 | 97.3 | 96.0* | 96.8 | 97.1 | ||
| V95 (%) | CW | 98.8 | 98.8 | 98.5 | 98.7 | 98.5 | |
| FIF | 96.2 | 95.5 | 96.3 | 95.9 | 96.2 | ||
| ISC | 99.2 | 98.7 | 96.9* | 98.7 | 99.0 | ||
| DHI (%) | CW | 4.9 | 4.9 | 5.0 | 5.0 | 5.0 | |
| FIF | 3.9 | 4.8 | 3.5 | 4.2 | 3.7 | ||
| ISC | 2.9 | 3.4 | 3.2 | 3.3 | 2.9 | ||
| Lung | V20 (%) | CW | 7.20 | 6.08 | 8.53 | 6.73 | 7.67 |
| FIF | 6.77 | 5.55 | 8.07 | 6.31 | 7.23 | ||
| ISC | 6.23 | 5.04 | 7.50 | 5.79 | 6.68 | ||
| Body | V105 (cm3) | CW | 114.66 | 112.80 | 117.50 | 108.64 | 122.36 |
| FIF | 5.04 | 16.65 | 5.42 | 6.66 | 6.26 | ||
| ISC | 0.29 | 5.41 | 2.73 | 1.13 | 1.13 |
CW = conventional wedge, FIF = field in field, ISC = irregular surface compensator, CTVevl = CTV for evaluation (see the detail in text), Mean = mean dose, D95 = dose covering ≥ 95% volume, V95 = volume receiving ≥ 95% prescribed dose, DHI = dose homogeneity index, V20 = volume receiving ≥ 20 Gy, V105 = volume receiving ≥ 105% prescribed dose, Original = original plan. aThe planning CT image (patient) movement direction. *Statistically significant difference from original plan.