Table 4.
AUC | 95% CI | Optimal threshold | Chi–square | ||||
---|---|---|---|---|---|---|---|
Value | Sensitivity/specificity (%) | P value | Odds ratio | ||||
Small bowel loops | V5 | 0.81 | 0.73–0.88 | 430 ml | 72.2/82.1 | <0.001 | 8.91 |
V10 | 0.82 | 0.74–0.89 | 360 ml | 77.8/76.1 | <0.001 | 8.30 | |
V15 | 0.82 | 0.75–0.89 | 395 ml | 72.2/82.1 | <0.001 | 12.21 | |
V20 | 0.83 | 0.75–0.90 | 330 ml | 83.3/73.5 | <0.001 | 8.30 | |
V30 | 0.87 | 0.81–0.93 | 300 ml | 83.3/77.8 | <0.001 | 31.51 | |
V40 | 0.89 | 0.82–0.95 | 225 ml | 94.4/70.9 | <0.001 | 19.16 | |
V45 | 0.88 | 0.82–0.94 | 235 ml | 88.9/74.4 | <0.001 | 27.20 | |
Mean dose | 0.73 | 0.63–0.83 | 36.7 Gy | 61.1/72.6 | 0.02 | 3.36 | |
gEUD (n = 0.15) | 0.75 | 0.65–0.84 | 46.0 Gy | 66.7/65.9 | <0.01 | 5.26 | |
Bowel bag | V30 | 0.69 | 0.59–0.79 | 940 ml | 72.2/57.3 | 0.06 | 3.24 |
V40 | 0.72 | 0.63–0.82 | 850 ml | 66.7/62.4 | <0.01 | 7.10 | |
V45 | 0.71 | 0.62–0.81 | 800 ml | 72.2/60.7 | 0.01 | 4.59 | |
Mean dose | 0.66 | 0.54–0.79 | 35.3 Gy | 61.1/69.2 | 0.16 | 2.15 | |
gEUD (n = 0.15) | 0.71 | 0.61–0.82 | 45.2 Gy | 65.8/66.7 | 0.11 | 3.28 |
ROC = receiver operating characteristics, DVH = dose–volume histogram, GI = gastrointestinal, AUC = area under the ROC curve, CI = confidence interval, gEUD = the generalized equivalent dose.