Table 2.
Diagnostic performance for assessment of residual tumour
| T2W‐MRI | T2W + DW‐MRI | |||||
|---|---|---|---|---|---|---|
| Reader 1 | Reader 2 | Reader 3 | Reader 1 | Reader 2 | Reader3 | |
| Sensitivity (%) | 100 | 90 | 90 | 95 | 97 | 90 |
| (89, 100) | (75, 97) | (75, 97) | (81, 99) | (85, 100) | (75, 97) | |
| Specificity (%) | 8 | 25 | 25 | 50 | 42 | 42 |
| (0, 40) | (7, 57) | (7, 57) | (22, 78) | (17, 71) | (17, 71) | |
| PPV (%) | 78 | 80 | 80 | 86 | 84 | 83 |
| (64, 88) | (64, 90) | (64, 90) | (71, 94) | (70, 93) | (68, 92) | |
| NPV (%) | 100 | 43 | 43 | 75 | 83 | 56 |
| (6, 100) | (12, 80) | (12, 80) | (36, 96) | (37, 99) | (23, 85) | |
| True‐positive | 39 | 35 | 35 | 37 | 38 | 35 |
| False‐positive | 11 | 9 | 9 | 6 | 7 | 7 |
| True‐negative | 1 | 3 | 3 | 6 | 5 | 5 |
| False‐negative | 0 | 4 | 4 | 2 | 1 | 4 |
| Accuracy (%) | 78 | 75 | 75 | 84 | 84 | 78 |
| AUC* | 0·65 | 0·66 | 0·68 | 0·71 | 0·70 | 0·70 |
| (0·47, 0·83) | (0·49, 0·83) | (0·51, 0·86) | (0·52, 0·90) | (0·52, 0·88) | (0·51, 0·88) | |
Values in parentheses are 95 per cent confidence intervals. Residual tumour (tumour regression grade 2–5 in resected primary tumour) was considered the positive outcome. T2W, T2‐weighted; DW, diffusion‐weighted; PPV, positive predictive value; NPV, negative predictive value; AUC, area under the receiver operating characteristic curve.
*
Comparison of T2W‐MRI versus T2W + DW‐MRI: P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively (DeLong test33).