Recombinant human thyrotropin-aided radioiodine treatment of differentiated thyroid carcinoma

Objective To observe the influence of recombinant human thyrotropin(rhTSH)on serum concentration of endogenous thyrotropin(TSH), free triiodothyronine(FT3), free thyroxine(FT4), thyroglobulin antibody(TGAb), and thyroglobulin(Tg). To evaluate the efficacy of rhTSH-aided radioiodine treatment in patients with differentiated thyroid carcinoma(DTC). Methods The study recruitment took place between November 2007 and March 2009. 62 patients(including 45 females)with biopsy confirmed DTC had undergone total or nearly total thyroidectomy, and received 131I treatment. 31 patients(including 22 females), median age of 45 years(23-72), received radioiodine treatment 4 weeks after L-thyroxine(T4)withdrawal. The other 31 patients(including 23 females), median age of 44 years(14-70), underwent rhTSH-aided radioiodine treatment. Before and after rhTSH injection, serum TSH, FT3, FT4, TGAb, and thyroglobulin were tested. Post-radiotherapy whole body scan was performed 5 to 7 days after radioiodine treatment and qualitatively and blindly evaluated by two nuclear medicine physicians. Follow-up took place 6 to 12 months after radioiodine treatment. The efficacy of rhTSH-aided radioiodine treatment was evaluated by whole body scan with diagnostic dose radioiodine. SPSS 13.0 statistical software was applied. Results (1)Before and after rhTSH-aided radioiodine treatment, the serum TSH was(1.08±4.01)vs(140.26±27.20)mIU/L(P＜0.05), thyroglobulin(23.75±132.92)vs(169.58±178.49)μg/L(P＜0.05), FT3(4.52±1.16)vs(4.42±1.11)pmol/L(P＞0.05), and FT4(15.09±5.83)vs(13.66±5.85)pmol/L(P＞0.05),respectively.(2)rhTSH-aided radioiodine ablation treatment had the same effect as L-T4withdrawal aided. The complete response ratio was 77.4% vs 71.0%(P＞0.05)by radioiodine whole body scan of diagnostic dose. Conclusion rhTSH-aided radioiodine treatment of DTC was effective and safe, and did at least at equivalent degree as did L-T4withdrawal. Furthermore, Serum thyroglobulin level could be effectively stimulated by rhTSH with tumor relapse or metastasis. Key words: Thyroid neoplasms; Recombinant human thyroid-stimulating hormone; Radioiodine treatment; Iodine radioisotope