BACKGROUND: Percutaneous ethanol injection (PEI) has been shown to be a valuable treatment for thyroid nodular pathology and metastatic cervical adenopathies.
OBJECTIVE: To evaluate the effectiveness, safety, and cost-effectiveness of PEI in thyroid nodular pathology and metastatic cervical adenopathies.
METHODS: A systematic review (SR) using meta-analysis was conducted on the effectiveness and safety of PEI. A SR on cost-effectiveness was also performed. The SRs were conducted according to the methodology developed by the Cochrane Collaboration with reporting in accordance with the PRISMA statement. A cost-minimization analysis was carried out using a decision tree model. Assuming equal effectiveness between two minimally invasive techniques (PEI and radiofrequency ablation (RFA)), the model compared the costs of the alternatives with a horizon of six months and from the perspective of the Spanish National Health System.
RESULTS: The search identified three RCTs (n=157) that evaluated PEI versus RFA in patients diagnosed with benign thyroid nodules: ninety-six patients with predominantly cystic nodules and sixty-one patients with solid nodules. No evidence was found on other techniques or thyroid nodular pathology. No statistically significant differences were observed between PEI and RFA in volume reduction (%), symptom score, cosmetic score, therapeutic success and major complications. No economic evaluations were identified. The cost-minimization analysis estimated the cost per patient of the PEI procedure at €326 compared to €4781 for RFA, which means an incremental difference of -€4455.
CONCLUSIONS: There are no differences between PEI and RFA regarding their safety and effectiveness, but the economic evaluation determined that the former option is cheaper.

OBJECTIVE: To evaluate the long-term efficacy of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.
METHODS: 100 subjects (48±12 years; 58% women) with symptomatic thyroid cysts relapsing after drainage were prospectively included. PEIT was conducted using an established procedure, and the initial cyst volume, symptoms and pain perceived by the patient were assessed. The volume of instilled alcohol was ≤2ml without re-extraction in all cases. Patients were followed-up for more than 3 years and final cyst volume and symptom improvement were assessed.
RESULTS: Mean maximum cyst diameter before drainage was 3.1±1.2cm. In 71% of patients ≤2 PEIT sessions were required. Median maximum cyst volume was 12.7 (5.4-21.7)ml before the first drainage and median total volume extracted from the cysts was 13.0 (6.2-37.0)ml. After a mean follow-up period of 52±10 months, 98% of patients reported a complete absence of symptoms. The final median volume for the whole group was 0.8 (0.1-2.0)ml with a median volume reduction of 94 (81-99)%. A final volume reduction greater than 65% was observed in 90% of cases. Reported pain during the procedure was absent or mild in 76.4% of cases.
CONCLUSIONS: PEIT is a safe and well-tolerated first-line treatment for symptomatic thyroid cysts with long-term effectiveness.

OBJECTIVE: To evaluate the long-term efficacy of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.
METHODS: 100 subjects (48±12 years; 58% women) with symptomatic thyroid cysts relapsing after drainage were prospectively included. PEIT was conducted using an established procedure, and the initial cyst volume, symptoms and pain perceived by the patient were assessed. The volume of instilled alcohol was ≤2ml without re-extraction in all cases. Patients were followed-up for more than 3 years and final cyst volume and symptom improvement were assessed.
RESULTS: Mean maximum cyst diameter before drainage was 3.1±1.2cm. In 71% of patients ≤2 PEIT sessions were required. Median maximum cyst volume was 12.7 (5.4-21.7)ml before the first drainage and median total volume extracted from the cysts was 13.0 (6.2-37.0)ml. After a mean follow-up period of 52±10 months, 98% of patients reported a complete absence of symptoms. The final median volume for the whole group was 0.8 (0.1-2.0)ml with a median volume reduction of 94 (81-99)%. A final volume reduction greater than 65% was observed in 90% of cases. Reported pain during the procedure was absent or mild in 76.4% of cases.
CONCLUSIONS: PEIT is a safe and well-tolerated first-line treatment for symptomatic thyroid cysts with long-term effectiveness.