Over sized .iso file to burn DVD

I have a backed up DVD in .ios format. It is over 7Gigs and I want to burn it to a 4.7Gig standard DVD. I have tried DVD Shrink, but will not open .IOS files, I currently have Nero 7Ultra Edition, it picks up just one part of the .ios file. I have tried DVD Decrypter to burn the file however I run into the size question again.
Has anyone got any suggestions on how to burn this file to a standard DVD?
Thank you

if your ISO files are movies, u can try ImTOO DVD Copy Express, which can automatically compress your 7G ISO files and burn them to DVDƔ.7G).