Outcome of palliative embolization of bone metastases in differentiated thyroid carcinoma

We investigated the effects of selective embolization in patients with symptomatic bone metastases of differentiated thyroid carcinoma. A total of 41 embolizations was performed in 16 patients. We studied the follow-up (range, 2 months to 8.6 yr) after the first embolization by evaluation of clinical symptoms and tumor dimensions. Success was defined as an improvement in clinical symptoms without tumor progression. The procedure was successful in 24 of 41 occasions (59%). Twenty-six embolizations were preceded or followed up by additional therapies, consisting of surgery (laminectomy), external irradiation, or radioiodine. Subgroup analysis revealed that these additional therapies did not influence the success rate; however, a potential effect on success duration may be present: for embolizations without additional radioiodine or external irradiation therapy, the median success duration was 6.5 months; for embolizations combined with additional radioiodine or external irradiation, this was 15 months (P = 0.0146). The ultimate outcome of the patients was unfavorable: nine patients died and five patients have progressive disease. We concluded that selective embolization of bone metastases may be considered a palliative therapy that may induce rapid, but transient, relief of symptoms. Combination with radioiodine or external irradiation may prolong the duration of success.