Table 2.
Comparison of target coverage data (median values, range)
| Dosimetric data | Standard tangential | 5-fields technique | p-value |
|---|---|---|---|
| HI | |||
| Median | 10.1 | 8.4 | <0.001 |
| Range | 7.1–38.6 | 6.8–16.5 | |
| CI | |||
| Median | 1.0 | 1.0 | 0.795 |
| Range | 0.7–1.0 | 0.9–1.0 | |
| PTV V95% (%) | |||
| Median | 98.9 | 98.9 | 0.752 |
| Range | 71.9–99.9 | 95.1–99.9 | |
| PTV V105% (%) | |||
| Median | 4.5 | 1.9 | <0.001 |
| Range | 0.1–9.3 | 0.0–6.4 | |
| PTV Dmax% (%) | |||
| Median | 108.9 | 106.9 | <0.001 |
| Range | 105.1–117.0 | 105.2–111.0 | |
| PTV Dmax (Gy) | |||
| Median | 54.1 | 53.4 | <0.001 |
| Range | 52.7–57.5 | 52.5–55.3 | |
CI, conformity index; HI, homogeneity index; PTV, planning target volume.
HI = 100 × (D2% − D98%)/prescribed dose.
CI = volume of PTV encompassed by 95% of the prescribed dose/PTV volume.