Methods and apparatus provide therapeutic electromagnetic radiation (EMR) for inactivating infectious agents in, on or around a catheter residing in a patient's body cavity and/or for enhancing healthy cell growth. The method comprises transmitting non-ultraviolet therapeutic EMR substantially axially along an optical element in a lumen of the catheter body and/or the catheter body. Through delivery of the therapeutic EMR to particular infected areas and/or areas requiring tissue healing. The methods and apparatus of the present disclosure inactivate the major sources of infection in, on, and around catheters and/or enhance healthy cell growth around catheters.