No. Only Dragonball and Dragonball Z occurred in the manga, making Dragonball GT technically filler--not canon. And the only few things akira toriyama did for gt, was the ss4 goku pic, and such minor stuff, so the answer is stil no well gt isn't based on manga but Toriyama supervised it,super saiyan 4 is considered as canon,because Akira Toriyama draw it. The series isn't considered canon.