A 66-year-old man with follicular thyroid cancer after total thyroidectomy was referred for 131I therapy. Thyroid function tests before 131I administration exhibited severe thyrotoxicosis although the patient did not take levothyroxine after thyroidectomy. A 185 MBq 131I whole-body scintigraphy and SPECT/CT revealed multiple iodine-avid pulmonary metastases with the largest tumor diameter of 1.4 cm and remnant thyroid. A diagnosis of thyrotoxicosis caused by hyperfunctioning pulmonary metastases was then made. The patient was administered 7.4 GBq of 131I. Six months after 131I therapy, a significant reduction of the pulmonary metastatic disease and thyroglobulin level was observed. However, the remnant thyroid was still visualized.
From the Departments of *Nuclear Medicine
‡General Surgery, West China Hospital, Sichuan University, Sichuan, China.
Received for publication November 17, 2018; revision accepted December 15, 2018.
Tian Tian and Yu Chen are equal contributors.
Conflicts of interest and sources of funding: None.
Author contributions: All named authors have agreed to the submission and have participated in the study to a sufficient extent to be named as authors should accompany the submitted manuscript. Tian Tian, manuscript writing. Yu Chen, Yongzhao Xiang and Lina Liu, data collection. Bin Liu, study design and manuscript editing.
Correspondence to: Bin Liu, MD, PhD, Department of Nuclear Medicine, West China Hospital, Sichuan University, No. 37 Guo Xue Alley, Chengdu 610041, Sichuan, China. E-mail: firstname.lastname@example.org.