J Korean Soc Endocrinol.  1999 Jun;14(2):323-329.

Comparosin of Pretreatment and Postreatment Whole Body Iodine-131 Scans in Patients with Differentiated Thyroid Carcinoma

• Kim ES
• Song YK
• Ryu JS
• Moon DH

Abstract

BACKGROUND: Whole body 131I scan is routinely performed in the postoperative evaluation of patients with differentiated thyroid carcinoma to detect recurrence and functioning metastasis. Previous reports suggested that posttreatment whole body scan had higher rate of detecting metastatic lesions that were not visualized by pretreatment images. We observed the frequency of discordance of the two scans and analysed the clinical significances. METHODS: Forty-one patients with differentiated thyroid carcinoma underwent radioactive iodine-131 whole body scans after administration of diagnostic dose (4 mCi) and then therapeutic dose (100~200 mCi of iodine-131). The median age of the patients was 46.9 +/- 15.7 years (range, 17~76). RESULTS: In 16 of the 41 patients (39.0%), pretreatment scan showed additional uptakes that were not seen in the pretreatment scan. Serum thyroglobulin was elevated in 13 of the 16 patients. Of the 22 patients who had been received radioactive iodine therapy previously, eight patients showed new additional lesions in the therapeutic scans but there was no significance according to the history of radioactive iodine therapy, Addisional uptakes after therapeutic dose were noted in neck area in 9 cases, lung in 2 cases, bone in 4 cases and mediastinum in one case. Diffuse hepatic uptake was definitely seen in 7 cases and there were 2 cases whose scans showed liver uptake without any thyroid uptake. CONCLUSION: Posttreatment whole body scan is more sensitive to detect residual tissues and metastasis compared to the usual pretreatment diagnostic whole body scan, and it is suggested that posttreatment whole body scan should be routinely performed after 'I therapy in patients with differentiated thyroid carcinoma for exact evaluation.

MeSH Terms

Humans
Iodine
Liver
Lung
Mediastinum
Neck
Neoplasm Metastasis
Recurrence
Thyroglobulin
Thyroid Gland*
Thyroid Neoplasms*
Whole Body Imaging
Iodine
Thyroglobulin