No definitive answer as to whether there is lingering infection, or cause of headaches, but infectious disease dr believes it's wise to take a wait and see position, go ahead with six weeks of proton therapy for second meningioma (really don't want to go through another crainiotomy), and, if symptoms of infection do appear, treat with antibiotics until PT is over, then deal with infection and possible surgery then. Thank you for your comments, Colleen.