Comparing dual phase Tl-201 thyroid scan and fine-needle aspiration cytology to detect follicular carcinoma.
It remains difficult to pre-operatively differentiate follicular carcinoma and adenoma even under intraoperative investigations including histopathologic diagnosis of frozen sections.


METHODS
We retrospectively compared dual phase thallium (Tl-201) thyroid scan and fine-needle aspiration (FNA) cytology to detect follicular carcinoma in 12 patients with cold thyroid nodules. Fine-needle aspiration cytology results were assessed and categorized by experienced pathologists into benign, suspicious, and malignant. Dual phase Tl-201 thyroid scan including an early (10-min) image and a delayed (3-hour) image were acquired after 2 mCi (74 MBq) of Tl-201 was injected intravenously. Dual phase Tl-201 thyroid scan findings were visually interpreted as positive and negative results.


RESULTS
Based on FNA cytologic interpretation criteria, three nodules were diagnosed as benign, five nodules were diagnosed as suspicious, and four nodules were diagnosed as malignant. However, based on dual phase Tl-201 thyroid scan interpretation criteria, all of the 12 nodules could accurately diagnose as malignant.


CONCLUSIONS
We conclude that dual phase Tl-201 thyroid scan was more accurate in diagnosing follicular carcinoma when comparing with FNA cytology.
Leung
Hung-Cheung
HC
Division of General Surgery, Department of Surgery, Show Chwan Memorial Hospital, Changhua, Taiwan.
Chang
Chwen-Tzuei
CT
Wu
Hurng-Sheng
HS
Wang
Tzu-Yuan
TY
Sun
Shung-Shung
SS
Kao
Chia-Hung
CH
D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging* / Q000473:pathology*; D000328:Adult; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013670:Sodium Pertechnetate Tc 99m; D013794:Thallium Radioisotopes; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000473:pathology
D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D013670:Sodium Pertechnetate Tc 99m