Desley van Zoggel

MRI tumour regression grade 109 CHAPTER 6 The agreement between the other abdomen radiologist and the pTRGwas fair (k =0.25; 95 percent CI 0.14-0.35) using the five-tier grading, as well as when using the two-tier grading system (k = 0.39; 95 percent CI 0.22-0.56) (Table 2). Interobserver agreement The mrTRG scores for both radiologists are shown in Table 3. The interobserver agreement between the two radiologists was moderate when using the five-tier regression scale (k = 0.44; 95 percent CI 0.34-0.54) and fair when using the adjusted regression scale comparing good responders (mrTRG 1-2) with intermediate/poor responders (mrTRG 3-5, k = 0.28; 95 percent CI 0.12-0.44). Figure 5. MRI at baseline and post chemoradiotherapy showing a slight radiological response (i.e. mrTRG 4). In this case, restaging was performed > 7 weeks Sensitivity, specificity, PPV, NPV Overall, sensitivitywas 46percent (95percent CI 30percent-63percent), specificitywas 99 percent (95 percent CI 94 percent-100 percent), PPV was 95 percent (95 percent CI 71 percent-99 percent), and NPVwas 80 percent (95 percent CI 75 percent-84 percent) for the lead radiologist for predicting a good response (i.e. Mandard 1-2). For the second radiologist, sensitivity was 64 percent (95 percent CI 47 percent-79 percent), specificity was 76 percent (95 percent CI 66 percent-85 percent), PPVwas 56 percent (95 percent CI 44 percent-66 percent), and NPVwas 82 percent (95 percent CI 75 percent-88 percent) for the lead radiologist for predicting a good response (Mandard 1-2).