Ultrasonography Guided Percutaneous Ethanol Injection Therapy for Benign Thyroid Nodules: Preliminary Experience

Thyroid nodule is one of the most frequently encountered thyroid diseases. High resolution ultrasonography (US) is sensitive and capable of detecting detailed anatomy of thyroid including nodules. Tc-99m thyroid scan is a well established and inexpensive imaging modality for many thyroid disorders. The aim of this study was to detect the effectiveness of percutaneous ethanol injection therapy (PEIT) in benign cystic thyroid nodules. Twelve cystic nodules in 12 consecutive patients were enrolled in this study. Morphological evaluation and volumetric assessment of each nodule was calculated using linear transducer (7.5-10 MHz). Thyroid scan, FNA and thyroid hormone status was evaluated. After aspiration of cyst fluid, 99% ethanol was injected in each nodule under US guidance. The effectiveness of sclerotherapy was assessed by comparing the baseline volume and the volume at final follow up 1-6 years following ethanol injection. The entire group had a highly significant reduction in the initial cyst volume compared with the final volume at the late follow-up after completion of PEIT (P<0.001). We found negative correlation between total volume and number of ethanol injection with the volume reduction rate (R linear = 0.224 & 0.226) respectively. Baseline Tc-99m thyroid scan showed cold area in all seven cystic nodules & three complex nodules (total 83.33%) and rest two complex nodules (16.67%) were partially cold. However, in the final follow up Tc-99m scan, no focal sign or any cold area was detected in five cases (41.67%). Rest seven cases (58.33%) showed reduction of nodule size and improved functional status revealed as radiotracer distribution at the previous cold nodular areas. In conclusion, US-guided percutaneous ethanol injection is an effective, safe, well-tolerated and inexpensive outpatient procedure for the treatment of benign cystic thyroid nodules.