The first time I did xD
I've got the link to the movie:
http://youtube.com/watch?v=UeG4IV5ZhzU
You know the episodes where Trunks goes back in time? This film is about what would happen in the future. At first Gohan runs home and Goku died of the Vital Heart Disease before Gohan got there.
Obviously Trunks went back in time so that Gohan or the rest wouldn't get killed and gave Goku the Antidote xD