Table 2.
Comparison of three-dimensional (3DCT) and four-dimensional (4DCT) computed tomography simulation results of vital organ at risk (OAR) doses
| Organs | 3DCT | 4DCT | p |
|---|---|---|---|
| PTV [cm3] | 460 ± 179 | 401±167 | 0.0018 |
| Mean lung dose [Gy] | 18.3 ± 4.00 | 16.9 ± 3.30 | 0.020 |
| V5% [Gy] | 59.9 ±12.30 | 44.6 ± 10.20 | 0.049 |
| V10% [Gy] | 55.8 ±11.70 | 31.2 ± 6.90 | 0.008 |
| V20% [Gy] | 40.5 ±8.60 | 28.9 ± 6.90 | 0.027 |
| V30% [Gy] | 28.9 ±6.90 | 25.3 ± 7.20 | 0.129 |
| Mean heart dose [Gy] | 15.8 ± 16.80 | 13.1 ±12.20 | 0.473 |
| Maximum spinal cord dose [Gy] | 40.0 ± 6.30 | 37.9 ± 6.10 | 0.116 |
| Mean esophagus dose [Gy] | 19.1 ± 7.50 | 18.7 ± 8.02 | 0.680 |
| NTCP to the lungs (%) | 31.75 ± 9.15 | 26.96 ± 7.40 | 1.54e-05 |
| NTCP of the heart (%) | 11.18 ± 10.02 | 7.78 ± 6.73 | 0.0018 |
| NTCP of the esophagus | 21.17 ± 10.09 | 19.45 ± 10.91 | 0.060 |
| CI | 0.62 ± 0.122 | 0.62 ± 0.164 | 0.827 |
| DHI | 1.09 ± 1.11 | 1.10 ± 0.03 | 0.579 |
PTV — planning target volume; NTCP — normal tissue complication probability; CI — conformity index; DHI — dose heterogeneity index