In the last six years, 114 prostate-cancer patients at the Philadelphia VA Medical Center might have received radiation doses below what was prescribed, say hospital officials. The men underwent brachytherapy, in which radioactive rods or seeds were implanted in and around the prostate to destroy cancer cells. "The program was suspended as soon as the problem was discovered," hospital spokeswoman Fern S. Billet told the Philadelphia Inquirer. "We are in the midst of an investigation to find out what happened."