The present disclosure relates to systems and devices for positioning and placing multiple electrodes in a target surgical site. A guide block is disclosed which introduces electrodes into target tissue and includes an elongated, generally rectilinear bar having a plurality of slots defined therethrough. Each of the slots is configured to selectively receive and retain a corresponding electrode therein. The rectilinear bar is malleable and selectively bendable from a substantially linear configuration to a substantially curved configuration to facilitate positioning the guide block relative to target tissue.