摘要Background Alcohol has been used for treating simple renal cysts since 1981.Since then,various observational studies have examined the technique,but they differ significantly in the details of the procedures and efficacy measures used.This has made it difficult to assess the safety and efficacy of this technique.We carried out a randomized controlled trial to evaluate the efficacy and safety of ultrasound-guided alcohol sclerotherapy involving single-session multiple injections to treat simple renal cysts.Methods A total of 144 patients with simple renal cysts were randomly allocated to either the treatment group (ultrasound-guided percutaneous drainage and alcohol sclerotherapy with single-session multiple injections) or control group (ultrasound-guided simple percutaneous drainage).Follow-up CT scans of ablated cysts were collected 3 and 6 months after the procedure.The outcome was considered successful if cyst volume between baseline and 6 months decreased by at least 87.5％.Results Intention-to-treat analysis revealed an average volume reduction of 94.2％ in the treatment group and 50.8％ in the control group (P ＜0.0001).The percentage of patients achieving successful outcomes was 88.9％ (95％ CI 77.0％-100.0％) in the treatment group and 22.2％ (95％ CI 6.54％-37.9％) in the control group (P ＜0.0001).The corresponding results in the per-protocol analysis were an average volume reduction of 96.4％ in the treatment group and 50.8％ in the control group (P ＜0.0001).The percentage of patients achieving a successful outcome was 94.3％ (95％ CI 85.6％-100.0％) in the treatment group and 22.2％ (95％ CI 6.54％-37.9％) in the control group (P ＜0.0001).Conclusion Alcohol sclerotherapy involving single-session multiple injections is safe and efficacious in the treatment of renal cysts.(ChiCTR-TRC-10001114,http://www.chictr.org)