Liberal U.S. Supreme Court Justice Ruth Bader Ginsburg has completed a three-week course of radiation therapy to treat a cancerous tumor on her pancreas, a court spokeswoman said on Friday. The 86-year old justice, who has had previous cancer scares, tolerated the therapy well and no further treatment is required, spokeswoman Kathy Arberg said in a statement. An abnormality was first detected in July, and the tumor was identified following a biopsy performed on July 31 at Memorial Sloan Kettering Cancer Center in New York.