Percutaneous ethanol injection safe, effective for benign, cystic thyroid nodules
Percutaneous ethanol injection should be considered an effective and safe strategy for patients with recurrent symptomatic cystic or predominantly cystic thyroid nodules, according to a meta-analysis published in Clinical Endocrinology.
“Among image-guided thyroid ablations, percutaneous ethanol injection (PEI) has been the most widely used method in patients with symptomatic cystic thyroid nodules,” Andrea Palermo, MD, PhD, an endocrinologist in the unit of endocrinology and diabetes at Campus Bio-Medico University in Rome, and colleagues wrote in the study background. “PEI is associated with improved outcomes compared to simple aspiration or saline injection and has similar efficacy and safety, but higher simplicity and lower costs compared to other ablations. To date, data on the results of PEI have been limited to the first few months of follow-up in the majority of the reports. In addition, different criteria have been used to assess its efficacy. Obtaining more robust evidence on the durability of results over time by using consistent methods could allow a better estimation of the role of PEI compared to surgery in symptomatic patients with benign cystic thyroid nodules.”
In a systematic review and meta-analysis, Palermo and colleagues analyzed data from nine studies published between 2002 and November 2020 that assessed patients with benign, cystic thyroid nodules treated with PEI and later followed for at least 6 months (sample size range, 58 to 432 nodules). Among the studies, four were retrospective cohorts, one was prospective and one was a randomized controlled trial. Researchers evaluated data on volume reduction rate, compressive symptoms and cosmetic concerns, and assessed any associated complications. The primary outcome was volume reduction rate at 6, 12, 24, 36, 48, 60 and 120 months after PEI therapy. Researchers pooled the data across studies using a random-effects model.
Overall, volume reduction rate was 77% at 6 months, 81% at 12 months, 72% at 24 months, 68% at 36 months, 74% at 60 months and 69% at 120 months. Not enough data were available for a meta-analysis to be performed at 48 months, according to researchers. A volume reduction rate of at least 50% was reported in approximately 80% of treated nodules, irrespective of the time of assessment. Researchers observed reductions in compressive symptoms and cosmetic concerns from baseline through last available follow-up. There were no permanent complications.
“Several protocols for PEI are available, and they mainly differ in terms of the injected ethanol volume and its retention,” the researchers wrote. “The ethanol volume ranged from 25% to 100% of the aspirated volume, with one study using up to 1.5 mL/mL of the initial nodular volume. The systematic review did not find any significant difference favoring higher ethanol volumes; [with] ethanol being potentially associated with the necrosis of adjacent structures, it would be reasonable to inject the lowest effective volume.”