Usefulness of 99mTc-pertechnetate whole body scan with neck and chest SPECT/CT for detection of post-surgical thyroid remnant and metastasis in differentiated thyroid cancer patients

摘要

Objective: The aim of the study was to evaluate the usefulness of 99mTc-pertechnetate whole body scan (WBS) with neck and chest SPECT/CT for detection of post-surgical thyroid remnant and metastasis in differentiated thyroid cancer (DTC) patients. Methods: Fifty-six post total thyroidectomy patients were included. All patients were prospectively imaged with 99mTc-pertechnetate WBS with neck and chest SPECT/CT before 131I ablation. The post-ablative 131I WBS with SPECT/CT was performed at 5-7 days after receiving 131I. Both scans were directly compared to determine the concordance of sites and number of remnant and metastasis. Results: Overall per-patient analysis, the percentage of concordance between two scans was 96.4 %. In thyroid bed, lymph node, lung and bone subgroups, the percentage of concordance between two scans was 96.4, 92.9, 98.2 and 100 %, respectively. All of them show good correlation with unweighted kappa between 0.7 and 1. Overall per-lesion analysis, the percentage of concordance between two scans was 84 %. In thyroid bed, lymph node, lung and bone subgroups, the percentage of concordance between two scans was 89.5, 55, 82.6 and 50 %, respectively. Conclusions: Pre-ablative pertechnetate WBS with neck and chest SPECT/CT has good correlation for the detection of post-surgical thyroid remnant, cervical node and discrete lung nodule metastasis as compared to 131I WBS with SPECT/CT per-patient basis. Because 131I therapeutic activity is desired base on metastatic site and less concerning about the number of lesions, pre-ablative 99mTc-pertechnetate WBS with SPECT/CT was a good alternative tool to avoid radioiodine stunning in post-surgical DTC patients.