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Table 2 Interobserver agreement

From: Inter- and intraobserver agreement of the quantitative assessment of [99mTc]-labelled anti-programmed death-ligand 1 (PD-L1) SPECT/CT in non-small cell lung cancer

SPECT Observer A Observer B Observer C ICC (95% CI) ICC level of agreement
ROImax (mean ± SD) ROImax (mean ± SD) ROImax (mean ± SD)
Malignant lesion(s) ROI
 Primary lung tumour (T) 548 ± 150 560 ± 154 568 ± 157 0.94 (0.90–0.97) Good to excellent
 Lymph node metastasis (LN) 459 ± 167 461 ± 167 448 ± 163 0.97 (0.95–0.98) Excellent
Healthy reference tissue
 Blood pool (BP) 260 ± 80 295 ± 80 270 ± 83 0.90 (0.84–0.94) Good to excellent
 Lung (freehand) 249 ± 146 310 ± 157 251 ± 88 0.84 (0.75–0.90) Moderate to excellent
 Lung (AA) 279 ± 113 279 ± 108 250 ± 94 0.89 (0.82–0.93) Good to excellent
 Lung (C) 307 ± 121 286 ± 129 288 ± 128 0.88 (0.81–0.93) Good to excellent
 Liver (freehand) 1121 ± 274 1262 ± 288 1194 ± 274 0.97 (0.95–0.98) Excellent
 Liver (GOJ) 1116 ± 264 1185 ± 270 1219 ± 283 0.95 (0.92–0.97) Excellent
  ROImax ratio (mean ± SD) ROImax ratio ROImax ratio (mean ± SD) ICC (95% CI) ICC level of agreement
(mean ± SD)
Ratios
 T:BP 2.29 ± 0.98 1.99 ± 0.67 2.20 ± 0.77 0.83 (0.73–0.90) Moderate to good
 T:L (freehand) 2.56 ± 1.18 2.01 ± 0.71 2.40 ± 0.86 0.79 (0.68–0.88) Moderate to good
 T:L (AA) 2.10 ± 0.75 2.17 ± 0.86 2.41 ± 0.90 0.85 (0.77–0.91) Good to excellent
 T:L (C) 1.92 ± 0.71 2.20 ± 0.92 2.18 ± 0.88 0.80 (0.69–0.88) Moderate to good
 LN:BP 1.86 ± 0.65 1.65 ± 0.51 1.76 ± 0.66 0.87 (0.81–0.92) Good to excellent
  1. Malignant lesion and healthy tissue reference measurements (ROImax; mean ± SD) and their ratios of all three observers with intraclass correlation coefficient (ICC), their 95% confidence interval (CI) and descriptive ICC level of agreement
  2. AA aortic arch, BP blood pool, C carina, CI confidence interval, ICC intraclass correlation coefficient, GOJ gastroesophageal junction, L lung, LN lymph node metastasis, ROI region of interest, T primary lung tumour