Table 3.
Performance of CT for the prediction of tumor invasion of the MRF at different anatomical locations.
| Locations | MRF invasion | Observer 1 | Observer 2 | |
|---|---|---|---|---|
| − | + | AUC (95% CI) | AUC (95% CI) | |
| Low anterior | 3 | 8 | 0.50 (0.10, 0.90)* | 0.31 (0.00, 0.64)* |
| Low lat-post | 32 | 3 | 0.78 (0.60, 0.97) | 0.58 (0.19, 0.96) |
| Mid anterior | 10 | 7 | 0.71 (0.46, 0.97) | 0.66 (0.35, 0.97) |
| Mid-high lat-post | 77 | 8 | 0.88 (0.73, 1.00)* | 0.84 (0.66, 1.00)* |
| All locations** | 122 | 26 | 0.82 (0.73, 0.92) | 0.70 (0.56, 0.84) |
Note: AUC = area under the ROC curve with 95% confidence interval; − = number of cases with a tumor free MRF predicted on MRI; + = number of cases with a tumor threatened or invaded MRF
* Statistically significant difference P ≤ 0.04
** Locations with normal rectal wall on MRI were excluded from analysis (120/268)