Figure 11. Between-Method Serum Tg Variability in DTC Patients +/- TgAb. Serum Tg measured by different methodologies in patients with distant metastatic DTC who were either TgAb-negative (panel A) or TgAb-positive (panel B). Three Tg methodologies were compared: IMA, LC-MS/MS (MS-M = Mayo; MS-Q = Quest), and RIA. Tg measurements below the assay FS limit are indicated in the shaded areas and expressed as a percentage relative to the total number of tests performed with that method. Patients who died of DTC-related complications are shown by solid symbols. From reference 14.