Brandt, a childhood pal of Hedican's, succumbed to a brain tumor and left behind a wife and two young children on March 2, 2008 in Mahtomedi, Minn. He was 37 years old.
On August 21, Yamaguchi and Hedican will host The Patrick Brandt Live Life, Give Love Celebration benefit concert and silent auction at The Myth Nightclub in Maplewood, Minn., to raise money for Brandt's family.
"Patrick was one of those guys who had a great sense of humor and a really positive outlook," Hedican tells PEOPLE of his friend. "He touched so many people with his positiveness. We want to celebrate his life, which ended far too early."
Rob Thomas headlines the show, which will also feature performances by Dancing pros Mark Ballas and Derek Hough's band, Almost Amy. Yamaguchi and Ballas, Dancing's season six champs, will also perform a dance or two.