1. Department of Surgery, Division of Urology, Faculty of Medicine, Universitas Sumatera Utara - Haji Adam Malik General Hospital, Medan, Indonesia
2. Department of Urology, Universitas Sumatera Utara Hospital, Universitas Sumatera Utara, Medan, Indonesia
3. Department of Urology, Faculty of Medicine, Universitas Indonesia - Haji Adam Malik General Hospital, Medan, Indonesia