Radioiodine and percutaneous ethanol injection in the treatment of large toxic thyroid nodule: A long-term study

Surgery is generally recommended for large thyroid toxic nodules (TTNs). Wh en surgery is not applicable, both radioactive iodine (RAI) and percutaneou s ethanol injection (PEI) are alternative treatments. In this retrospective study, the long-term efficacy of nonsurgical treatments was evaluated in 4 3 patients with TTN, selected on the basis of presence of hyperthyroidism a nd a fairly large nodule (3- and 4-cm in diameter) completely inhibiting co ntrolateral lobe captation during scintigraphy. Twenty-one patients were tr eated by RAI (administered dose 670 +/- 160 MBq; range 555-925) and twenty- two were treated by PEI (6 +/- 1 sessions; range 5-9). FT4, FT3, thyrotropi n (TSH), and nodule volume were assessed before and at fixed intervals afte r treatment. Median follow-up was 36 months (range, 12-84). Compared to bas eline values, with both therapies, serum FT4, FT3, and nodule volume were d ecreased (p < 0.01) and serum TSH was increased (p < 0.01), after 3 months and during the entire follow-up. Nodule volume reduction percentage was 66. 8 +/- 22.0 and 78.4 +/- 18.0, in the RAI- and PEI-treated groups, respectiv ely. At the end of follow-up, 34 patients were euthyroid (16 RAI- and 18 PE I-treated). Four RAI-treated patients (19%) showed slightly high TSH levels (4.2-5.3 mU/L), whereas three PEI-treated patients (13.6%) still had suppr essed TSH levels, although being clinically asymptomatic. One RAI-treated p atient (4.8%) showed overt hypothyroidism during the follow-up period and w as then treated with L-thyroxin. One patient (4.6%), who was initially cure d by PEI, became newly hyperthyroid during the followup period. Both treatm ents were well-tolerated, in conclusion, both of these nonsurgical treatmen ts are effective and may be chosen also for relatively large TTNs. Specific ally, RAI seems to be more effective for treating hyperthyroidism but has m inimal sequelae of subclinical or clinical hypothyroidism, while, after PEI treatment the possibility of stable subclinical hyperthyroidism or hyperth yroidism relapse should be taken into account.