A fluorescent tracer for targeting tumors, comprises: at least one first fluorophore fluorescing in a range of wavelengths of between 700 and 1000 nm, a targeting assembly comprising at least two identical targeting molecules, and a cyclic oligopeptide: configured so as to define a mean plane defining a first upper face and a second lower face, comprising at least one first lysine amino acid residue on the second lower face, the targeting molecules being fixed to the first upper face of the mean plane, the fluorophore being fixed to the second lower face of the mean plane via a spacer arm connecting a carbon of the sequence of the at least three double bonds and the lysine amino acid residue of the oligopeptide.