1. An energy application apparatus for applying energy to an object, wherein the object comprises a location with radioactive material and wherein the energy application apparatus comprises: a location detection unit being usable for detecting the location with the radioactive material, an x-ray unit for applying x-rays to the detected location of the object, and an interventional device being at least one of a handheld device and an in-body device, wherein the interventional device includes at least a part of the location detection unit and at least a part of the x-ray unit such that the location with the radioactive material is detectable and x-rays are applicable to the detected location via the interventional device; and wherein the location detection unit comprises an array of detection elements for detecting radiation from the radioactive material and for generating a detection signal being indicative of the detected radiation, wherein the array of detection elements is adapted to generate a spatial detection signal depending on the location of the respective detection element, wherein the energy application apparatus comprises a direction determination unit for determining a direction of maximal radioactivity based on the spatial detection signal, and wherein the direction determination unit is adapted to differentiate the spatial detection signal and to determine the direction of maximal radioactivity based on the differentiated spatial detection signal.