Role of Tc-99m pertechnetate for remnant scintigraphy, post-thyroidectomy, and serum thyroglobulin and antithyroglobulin antibody levels in the patients with differentiated thyroid cancer

One hundred and seventy-four patients (146 women, 28 men) with a mean age of 48.7 ± 13.1 (range 12–84) years who had undergone surgical thyroidectomy for DTC were evaluated retrospectively. Of 174 patients, 6 (3 %) had negative I-131 and also Tc-99m pertechnetate scintigraphy results. Of the remaining 168 positive I-131 scans, 131 (75 %) were positive in at least one site on the pertechnetate scan, 19 (11 %) were considered to have equivocal uptake and 18 (11 %) were negative. For the per-site analysis, pertechnetate sites were considered to be accurately determined if they showed concordant uptake at sites that correlated precisely with those seen on the postablation I-131 scans. There were a total of 356 positive foci on I-131 scans. Of these, 273 foci (77 %) were unequivocally positive on pertechnetate scintigraphy, 41 (11 %) showed equivocal uptake and 42 (12 %) foci could not be detected. There were statistically significant differences (p < 0.0001) between the negative and positive foci in terms of Tg levels on pertechnetate sites.