Therapeutic options for toxic thyroid nodules (TTNs) are surgery, radioiodine (RAI), and percutaneous ethanol injection (PEI). Surgery is generally considered for TTNs larger than 4 cm. However, some patients may be at high surgical risk. The purpose of the study was to evaluate the efficacy of 2 nonsurgical modalities for these TTNs.
Methods: Twenty-two patients with TTNs larger than 4 cm were randomly assigned to 2 different treatments: to 11 (subgroup A), RAI was administered at a dose of 12,580 kBq/mL of nodular volume (NV) and was corrected for 100% 24-h (131)I uptake (RAIU); to 11 (subgroup B), 2-4 PEI sessions (ethanol injected = 30% NV) preceded 2 mo of 24-h RAIU and RAI dosing. Inclusion criteria were clinical and biochemical hyperthyroidism; a single palpable, hot nodule at (99m)Tc scintigraphy; and high surgical risk or refusal to have surgery. Patients gave informed consent. Local symptoms were evaluated by a previously validated score (symptom score, or SYS).
Results: Both treatments were well tolerated. Subgroup B showed a significant reduction of NV 2 mo after PEI: 33.6 +/- 18.5 versus 60.8 +/- 29.5 mL. Their 24-h RAIU was similar to that of subgroup A: 53.9 +/- 13.9 versus 61.8% +/- 11.0%. Consequently, the administered RAI dose was significantly lower for subgroup B (730 +/- 245 MBq) than for subgroup A (1,048 +/- 392 MBq). Twelve months after RAI, subgroup B had a higher NV reduction and a lower SYS than did subgroup A. In subgroup A, 1 patient was subclinically hyperthyroid, 2 showed a slight increase of thyroid-stimulating hormone, and 1 was clinically hypothyroid. In subgroup B, 1 patient had a slight increase of thyroid-stimulating hormone.
Conclusion: We demonstrated that RAI, alone or with PEI, can be considered a valid alternative for TTNs larger than 4 cm when surgery is either refused or contraindicated. PEI plus RAI can be considered when marked shrinkage of a nodule is required or when reduction of the RAI dose can prevent hospitalization.