The confidence interval reported in this study appears to be an error

I was excited to read about the results of single fraction high-dose-rate monotherapy for prostate cancer as reported by Prada et  al. The study included 60 patients with a median follow-up of 5 years. The authors report 6-year biochemical control of 82%, which is impressive, but it is difficult for me to believe the reported 95% confidence interval of ±3% at 6 years. I ask the authors to recheck their calculations.
Source: Brachytherapy - Category: Cancer & Oncology Authors: Source Type: research