Can you create a DVD studio pro project from a DVD?

I have inherited a DVD project that needs updated. I have the original DVD that was burned, but the DVD studio pro project that was used to map and make it does not exist. I only want to add to the DVD. Is it possible to take a DVD that was burned in DVD studio Pro and open it so that you see the layout and links in studio pro and copy that DVD as a project? Or am I stuck remaking the dvd with links and buttons etc. from scratch?

Thanks for your help.