How to override delete option of context menu appeared upon right clicking on ROI defined by impoly?

I am drawing multiple ROIs on a image using impoly. Once an ROI is created the program automatically assign a name to each ROI using text(). Now the problem is when I delete a particular ROI by delete option in context menu appeared after right clicking on ROI, the ROI is deleted but name assigned to that particular ROI is still present. Is there any way I can modify the operation of delete function such that I can include a line of code to delete the string containing ROI name? Thanks