Embolization Therapy of Bone Metastases from Epithelial Thyroid Carcinoma: Effect on Symptoms and Serum Thyroglobulin

Background: Selective embolization therapy (SET) has been employed to treat a number of malignant tumors, but experience with its use in metastatic epithelial thyroid carcinoma (ETC) is limited. Here we report our experience with the effect of SET on symptoms and serum thyroglobulin (Tg) in patients with bone metastases from ETC. Methods: This was a retrospective study of 13 patients with bone metastases from ETC who underwent 65 embolizations for bone metastases in 43 sessions. In the treated patients, symptoms considered related to bone metastases were compared before and about 4-7 weeks after the embolization session. Embolization sessions were excluded for analysis if concomitant therapy had taken place within 4-7 weeks before and/or after the session. Serum Tg concentrations were employed as an index of tumor debulking by SET. We attempted to estimate the influence of SET on survival time in patients with disseminated ETC who did, and an historical control group of patients with disseminated ETC who did not receive SET. Results: After exclusion of 12 (of which 3 sessions failed) out of 43 sessions, clinical symptoms, such as pain, and neurological symptoms decreased after 17, increased after 6, and did not change after 8 procedures. In 43 sessions, 20 of which were excluded (including the 3 sessions that failed), serum Tg decreased after 14 and increased after 9. The median standardized survival time of the group that received embolization was not significantly different to that of the group that did not receive embolization. Conclusions: Embolization therapy does not appear to improve life expectancy, but in selected patients can achieve palliation of pain, prevent neurological damage, reduce tumor burden, and give devascularization of the tumor before surgery.