Aim: To study patients with Bone metastases in papillary carcinoma thyroid and the role of I-131 ablation.
Methods: Retrospective analysis of patients with papillary carcinoma of thyroid between 19602005 in our institution.
Results: Of 1538 patients who had thyroid carcinoma, papillary carcinoma was seen in 1228 (79.8%), and 21 patients with papillary carcinoma (1.71%) had bone metastases. Seventy percent of them were between 40 to 60 years of age. Total thyroidectomy was done in all patients except one. Seven patients had neck dissection for nodal disease. The pathological variants were insular, follicular, and micro carcinoma. Metastases were seen in ribs (7), pelvis(3), vertebra(4), skull(5), shoulder(2), humerus (1), femur(1). Eleven patients had skeletal metastasis in more than 2 sites. Secondaries in the rib were more common. The I-131 ablation dose ranged from 90 millicuries to 880 millicuries. Patients with rib secondaries responded well. Response to ablation was poor in 4 patients.Patients with moderate rise in thyroglobulin at the time of diagnosis had better response than subjects with very high level of serum thyroglobulin.
Conclusion: I-131 ablation has a role in the management of bone metastases. An initial higher value of serum thyroglobulin seem to be a predictor of poor response to ablation. In non responders, there is a role for repeated ablations up to 1000 millicuries.