Radioiodine therapy in skeletal metastases from well-differentiated thyroid cancer: a Johannesburg experience

Aim. The purpose of this study was to examine the outcome of patients with skeletal metastases from well-differentiated thyroid carcinoma and analyse the effect of variables that influence the prognosis of this disease. Method. We retrospectively reviewed 352 patients treated and followedup at the Charlotte Maxeke Johannesburg Academic Hospital's thyroid cancer clinic from 1982 -1999. Findings. Skeletal metastases were diagnosed in 24 (6.8%), 17 at presentation to the thyroid clinic, and 7 at follow-up. Patients' ages ranged from 30 -77 years (mean 53.9 years) and the female: male ratio was 3.8: 1. Based on the original pathology reports from resected tumours, 9 were papillary and 15 were follicular cancers. Twenty-three of the 24 patients underwent thyroid surgery as the initial management -total thyroidectomy in 18, subtotal thyroidectomy in 3, and lobectomy plus neck dissection in one. The diagnosis of thyroid cancer was based on lobectomy in a single subject. Radioactive iodine (RAI) was used as part of the original treatment; external radiation therapy (XRT) was mainly used to alleviate severe symptoms. Twenty-one patients (87.5%) were treated with RAI; 11 (45.8%) received radiotherapy. Seven patients died -4 from neurological disease directly associated with bone metastases. Of the 17 surviving patients, 2 appeared to be disease-free, 8 were asymptomatic despite overt bony disease, and 7 had persistent symptoms which much improved in 5. Bone metastases were uncommon, and follicular cancer predominated in this survey. Conclusion. RAI therapy improves quality of life in most patients. There is a place for XRT.