Dr. Johns collected depth-dose data at the University of Saskatchewan which would later become the world standard.[1] The first patient to be treated with cobalt-60 radiation was treated on October 27, 1951, at the War Memorial Children's Hospital in London, Ontario.[2][3] In 1961 cobalt therapy was expected to replace X-ray radiotherapy.[4] In 1966, Walt Disney's lung cancer was treated with this procedure, but could not prevent his death.