Abstract:

Objective To investigate the clinical features and imaging diagnosis of bone metastases from differentiated thyroid cancer (DTC). Methods The rate of bone metastases, age, clinical symptoms and signs, pathological types, metastatic sites and other concomitant metastases of 106 patients with bone metastases from DTC treated by ¹³¹I were retrospectively analysed. The sensitivities of MRI, ¹³¹I whole body scan, X-ray, CT and ^99mTc-MDP bone scan in the detection of bone metastases from DTC were compared. Results The rate of bone metastases was 8.43%(106/1 258), and most of the bone metastases were osteolytic lesions. Ribs, ilia and thoracic vertebrates were the most common sites of bone metastases from DTC. Bone metastases served as the initial presentation in 19.81% of patients, and multiple bone metastases were commonly occurred. The sensitivities of MRI, ¹³¹I scan, CT, X-ray and ^99mTc-MDP bone scan in the diagnosis of bone metastases were 96.59%, 93.84%, 66.49%, 47.46% and 38.19%, respectively, and there were significant difference in sensitivities between ¹³¹I scan and X-ray, CT and ^99mTc-MDP bone scan (P＜0.05）. Conclusion Bone metastases from DTC are characterized by multiple osteolytic lesions. MRI and ¹³¹I whole body scan are more sensitive in the diagnosis of bone metastases form DTC than CT, ^99mTc-MDP bone scan or X-ray.

Key words: differentiated thyroid cancer, bone metastasis, radioiodine