  We compute generalized absorption and extinction cross-sections of an optical
dipole nanoantenna in a structured environment. The expressions explicitly show
the influence of radiation reaction and the local density of states on the
intrinsic absorption properties of the antenna. Engineering the environment
could allow to modify the overall absorption as well as the frequency and the
linewidth of a resonant antenna. Conversely, a dipole antenna can be used to
probe the photonic environment, in a similar way as a quantum emitter.
