Table 3:
Summary of the dose indices on the isocenter-shift plan for the anterior-posterior direction
| Original 0 cm | Posta 1.0 cm | Posta 0.5 cm | Anta 0.5 cm | Anta 1.0 cm | |||
|---|---|---|---|---|---|---|---|
| CTVevl | Mean (%) | CW | 102.0 | 101.6 | 102.2 | 101.5 | 101.0 |
| FIF | 100.2 | 99.3 | 100.3 | 99.4* | 98.5* | ||
| ISC | 100.3 | 100.1 | 101.1 | 99.3* | 97.2* | ||
| D95 (%) | CW | 97.6 | 93.0 | 96.8 | 97.1 | 96.6 | |
| FIF | 95.8 | 88.2 | 93.8 | 95.7 | 94.3* | ||
| ISC | 97.3 | 87.7* | 95.8 | 94.9* | 90.2* | ||
| V95 (%) | CW | 98.8 | 95.8* | 98.3 | 98.4 | 97.6 | |
| FIF | 96.2 | 87.5* | 93.8 | 96.1 | 87.9* | ||
| ISC | 99.2 | 91.9* | 97.6* | 93.1* | 71.2* | ||
| DHI (%) | CW | 4.9 | 5.7 | 5.0 | 5.0 | 5.0 | |
| FIF | 3.9 | 7.8* | 5.5* | 3.6 | 4.4 | ||
| ISC | 2.9 | 6.4* | 4.2* | 3.5* | 5.8* | ||
| Lung | V20 (%) | CW | 7.20 | 3.49* | 5.24* | 9.20* | 11.34* |
| FIF | 6.77 | 3.15* | 4.84* | 8.74* | 10.85* | ||
| ISC | 6.23 | 2.77* | 4.37* | 8.16* | 10.25* | ||
| Body | V105 (cm3) | CW | 114.66 | 121.34 | 115.21 | 115.79 | 123.69 |
| FIF | 5.04 | 70.25* | 30.89* | 7.50 | 15.42 | ||
| ISC | 0.29 | 64.96* | 18.17* | 3.14 | 14.40* |
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, Post = posterior, Ant = anterior, Original = original plan. aThe planning CT image (patient) movement direction. *Statistically significant difference from original plan.