Table 5.
Comparison between the PTV dose coverage achieved by the TPS and the PTV dose coverage predicted by the IDVHs method.
| Structures | Parameters | TPS (Mean ± SD) | IDVHs (Mean ± SD) | diff (%) | p-value |
|---|---|---|---|---|---|
| Nasopharyngeal cancer | |||||
| PTV70 | D98 (Gy) | 69.85 ± 1.25 | 69.56 ± 1.28 | 2.63 ± 2.08 | 0.836 |
| D95 (Gy) | 70.76 ± 0.54 | 70.22 ± 1.95 | 2.11 ± 1.58 | 0.307 | |
| D1 (Gy) | 75.60 ± 1.00 | 75.55 ± 0.85 | 1.06 ± 1.09 | 0.848 | |
| UI | 1.07 ± 0.03 | 1.06 ± 0.02 | 2.02 ± 1.46 | 0.296 | |
| PTV60 | D98 (Gy) | 61.33 ± 0.94 | 61.95 ± 1.32 | 2.12 ± 1.72 | 0.052 |
| D95 (Gy) | 62.88 ± 1.07 | 63.17 ± 1.55 | 2.57 ± 2.43 | 0.201 | |
| PTV54 | D98 (Gy) | 53.60 ± 1.62 | 53.88 ± 1.34 | 3.15 ± 2.36 | 0.562 |
| D95 (Gy) | 55.44 ± 1.37 | 55.65 ± 1.15 | 2.45 ± 2.21 | 0.236 | |
| Rectal cancer | |||||
| PTV50 | D98 (Gy) | 50.83 ± 1.04 | 50.69 ± 1.74 | 2.95 ± 2.87 | 0.286 |
| D95 (Gy) | 51.59 ± 0.94 | 51.13 ± 1.66 | 2.57 ± 2.86 | 0.396 | |
| D1 (Gy) | 54.10 ± 0.62 | 54.12 ± 0.62 | 0.85 ± 0.76 | 0.550 | |
| UI | 1.04 ± 0.02 | 1.05 ± 0.03 | 2.63 ± 2.68 | 0.650 | |
| PTV45 | D98 (Gy) | 46.11 ± 0.74 | 45.86 ± 0.99 | 3.74 ± 3.85 | 0.753 |
| D95 (Gy) | 47.05 ± 0.83 | 46.85 ± 1.76 | 3.22 ± 3.63 | 0.995 | |
The data shown are the means and standard deviations of the respective parameters for the 20 nasopharyngeal cancer and 15 rectal cancer patients. diff represents the mean absolute percentage difference between the PTV dose coverage achieved by the TPS and the PTV dose coverage predicted by the IDVHs method. (diff =|PIDVHs-PTPS|/PTPS × 100%), where, P represents the corresponding parameter.