Table 1 Performance and threshold of the multiplex PCR ctDNA assay for single mutation detection
ctDNA concentration of standard | 0% | 0.10% | 0.25% | 0.50% | 1.0% | 3.0% | 6.0% | 10% | 15% |
|---|---|---|---|---|---|---|---|---|---|
 Number of replicates | 157 | 160 | 160 | 160 | 157 | 155 | 157 | 157 | 157 |
 Observed allelic frequency | |||||||||
  Mean | 0.065 | 0.122 | 0.276 | 0.577 | 1.132 | 3.380 | 6.358 | 9.858 | 15.2 |
  Std. deviation | 0.062 | 0.113 | 0.168 | 0.268 | 0.197 | 0.466 | 0.751 | 0.900 | 1.142 |
  Std. error of mean | 0.005 | 0.009 | 0.013 | 0.021 | 0.016 | 0.037 | 0.060 | 0.072 | 0.091 |
  Lower 95% CI of mean | 0.055 | 0.105 | 0.250 | 0.536 | 1.101 | 3.306 | 6.239 | 9.716 | 15.080 |
  Upper 95% CI of mean | 0.075 | 0.140 | 0.302 | 0.619 | 1.163 | 3.454 | 6.476 | 10.000 | 15.440 |
  Minimum | 0 | 0 | 0 | 0.020 | 0.660 | 2.100 | 4.740 | 7.660 | 11.690 |
  25% percentile | 0.010 | 0.030 | 0.123 | 0.373 | 1.010 | 3.050 | 5.800 | 9.290 | 14.310 |
  Median | 0.050 | 0.070 | 0.285 | 0.555 | 1.110 | 3.410 | 6.310 | 9.760 | 15.260 |
  75% percentile | 0.105 | 0.208 | 0.400 | 0.760 | 1.255 | 3.670 | 6.950 | 10.380 | 15.930 |
  Maximum | 0.230 | 0.410 | 0.760 | 1.430 | 1.770 | 4.940 | 8.200 | 14.430 | 18.490 |
  Coefficient of variation | 96.6% | 92.2% | 60.8% | 46.4% | 17.4% | 13.8% | 11.8% | 9.1% | 7.5% |
  Sensitivity (%, threshold = 0.127%) | NA | 40.6% | 75.0% | 96.3% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |