Table 3.
Correlations between factors and Dice similarity coefficient in gross tumor volume
| PET | CT | MRI | |||||||
|---|---|---|---|---|---|---|---|---|---|
| No | DSC (median ± SD)/ correlation coefficient (ρ) | p-value | No | DSC (median ± SD)/ correlation coefficient (ρ) | p-value | No | DSC (median ± SD)/ correlation coefficient (ρ) | p-value | |
| Primary site | |||||||||
| Oropharyngeal cancer | 5 | 1 | 1 | 5 | 0.42 ± 0.30 | 0.67 | 3 | 0.63 ± 0.11 | 0.29 |
| Other | 5 | 1 | 5 | 0.49 ± 0.28 | 5 | 0.45 ± 0.23 | |||
| Stage | |||||||||
| De novo | 7 | 1 | 1 | 7 | 0.44 ± 0.30 | 0.91 | 5 | 0.45 ± 0.23 | 0.3 |
| Recurrent | 3 | 1 | 3 | 0.47 ± 0.26 | 3 | 0.63 ± 0.11 | |||
| Dental artifacts and GTV on the same axial plane | |||||||||
| Yes | 5 | 1 | 1 | 5 | 0.40 ± 0.29 | 0.53 | 4 | 0.60 ± 0.11 | 0.56 |
| No | 5 | 1 | 5 | 0.51 ± 0.29 | 4 | 0.44 ± 0.26 | |||
| Size of GTV | ρ = 0.63 | 0.04 | ρ = 0.54 | 0.16 | |||||
| Distance between dental artifacts and GTV | ρ = -0.23 | 0.51 | ρ = −0.56 | 0.14 | |||||
PET = positron emission tomography, CT = computed tomography, MRI = magnetic resonance imaging, DSC = Dice similarity coefficient, GTV = gross tumor volume, SD = standard deviation