1. A method for controlling a device for determining a lesion location within a target site in a patient, the steps comprising: controlling movement of at least one photon imaging device that is configured to be movable with respect to the target site such that the at least one photon imaging device acquires a plurality of images relative to the target site, wherein a signal intensity is obtainable from opposing positions; receiving the plurality of images and the signal intensity for each of the plurality of images; and determining the lesion location in the patient based upon the plurality of images acquired by the at least one imaging device and using a single pair of signal intensities obtained simultaneously from the opposing positions.