Table 1.
Summary of the mean and one standard deviation of the dosimetric parameters obtained with PTV–based prescription
| 85% PIL | 80% PIL | 70% PIL | 60% PIL | |
|---|---|---|---|---|
| GTV Dmean (Gy) | 62.4 ± 1.5 | 66.2 ± 1.0 | a74.4 ± 1.1 | a84.2 ± 2.3 |
| PTV Dmean (Gy) | 58.7 ± 0.9 | 60.6 ± 0.7 | a63.9 ± 0.8 | a67.3 ± 1.7 |
| PTV D98% (Gy) | 53.6 ± 1.7 | 53.1 ± 0.2 | a52.9 ± 0.2 | a52.6 ± 0.4 |
| Spinal cord D1% (Gy) | 9.1 ± 2.9 | 10.0 ± 3.9 | 9.7 ± 3.8 | 10.2 ± 3.5 |
| Esophagus D1% (Gy) | 9.4 ± 3.6 | 9.6 ± 4.9 | 9.5 ± 5.2 | 9.6 ± 5.2 |
| Bronchus D1% (Gy) | 13.6 ± 7.6 | 13.2 ± 7.6 | 12.6 ± 7.2 | 12.0 ± 7.2 |
| Trachea D1% (Gy) | 5.3 ± 7.1 | 5.6 ± 7.4 | 5.1 ± 6.9 | 5.3 ± 7.3 |
| Chest wall/Rib V30Gy (cc) | 42.0 ± 35.7 | 34.7 ± 19.0 | 33.1 ± 22.1 | 30.2 ± 20.5 |
| Heart D1% (Gy) | 10.7 ± 9.4 | 10.5 ± 9.3 | 10.0 ± 9.0 | 9.8 ± 8.7 |
| PTV minus GTV D50% (Gy) | 57.6 ± 0.7 | 59.2 ± 0.4 | 61.4 ± 0.8 | 63.5 ± 1.2 |
| PTV minus GTV V54Gy (%) | 34.5 ± 16.4 | 34.3 ± 16.2 | 34.2 ± 16.2 | 34.0 ± 15.9 |
| Normal Lung MLD (Gy) | 5.0 ± 1.7 | 4.7 ± 1.4 | 4.6 ± 1.3 | 4.6 ± 1.4 |
| Normal Lung V30Gy (%) | 4.9 ± 2.8 | 4.5 ± 2.0 | 4.1 ± 1.9 | a4.0 ± 1.8 |
| Normal Lung V20Gy (%) | 8.4 ± 3.5 | 7.4 ± 3.0 | 7.1 ± 2.9 | a7.0 ± 2.9 |
| Normal Lung V10Gy (%) | 13.9 ± 4.9 | 13.0 ± 4.1 | a12.6 ± 3.6 | a12.5 ± 3.8 |
| Normal Lung V5Gy (%) | 19.5 ± 4.9 | 19.2 ± 4.4 | 18.9 ± 4.2 | 18.8 ± 4.2 |
| MU | 4717 ± 994 | a 4333 ± 868 | 4615 ± 1013 | 5011 ± 1031 |
| nCI | 1.08 ± 0.03 | 1.07 ± 0.02 | 1.07 ± 0.01 | 1.07 ± 0.01 |
| R 50% | 6.11 ± 1.42 | 5.73 ± 1.67 | 5.11 ± 1.26 | a5.00 ± 1.07 |
Abbreviations: GTV gross target volume, PTV planning target volume, Dmean mean dose, Dx% dose to x percent volume of the organ, VxGy percent volume of the organ receiving at least x Gy, MLD mean lung dose, MU monitor unit, nCI target dose conformity index, R50% dose gradient index, PIL prescription isodose line relative to the maximum dose. aSignificant difference from the reference 85% PIL