ABSTRACT
Objective To evaluate the efficacy of 131I treatment for bone metastases from DTC and analyze the survival rates after 131I treatment and prognostic factors. Methods One hundred and six DTC patients with bone metastases treated by 131I during January 1991 and January 2009 were retrospectively analyzed. Treatment efficacy was assessed based on serum Tg change, bone pain palliation and changes on medical imaging. Univariate analysis was performed for defining the factors affecting 131I treatment efficacy. Survival curves were estimated using the life table method. Survival analysis was performed using Kaplan-Meier method. Results Serum Tg decreased dramatically in 37/106 (34.9%) patients treated with131I. Thirty-nine of 61 patients (63.9%) with bone pain had pain relief. Age, tumor subtype and presence of non-osseous distant metastases were significant factors affecting 131I treatment efficacy based on serum Tg change (χ2=6.443, 11.455, 6.756, all P0.05). There were no imaging changes of bone metastases in 77.4% of patients after 131I treatment. The overall 5-year and 10-year survival rates from initial diagnosis of bone metastases was 86.47% and 57.90%, respectively. Univariate analysis showed that number of metastases, presence of non-osseous distant metastases and pre-131I treatment surgery were significant factors for survival (Log-rank values were 4.05, 5.98, 4.22, all P<0.05). Conclusions 131I treatment for bone metastases from DTC is effective for lowering serum Tg and palliation of bone pain. Single metastasis, absence of non-osseous distant metastases and pre-131I therapy surgery are favorable predictors of prognosis.