How to remove default close button in RadDesktopAlert control of telerik for wpf, is this possible?

public RadDesktopAlertManager ExecuteBatchDesktopAlert=new RadDesktopAlertManager(AlertScreenPosition.BottomRight,new Point(5,5),5); public void ShowNotification(string header, string content) { var radAlert = new RadDesktopAlert {
Header = header, Content = content, Height = 90, Width = 300, Opacity = 1, Background = Brushes.Gray,

        };
        ExecuteBatchDesktopAlert.ShowAlert(radAlert);            
    }