A miniaturized radiation device, having a support member in the form of a flexible sheet, and a circuit pattern of electrical contact pads and interconnecting conductor lines or leads provided on said support member. The pads are interconnected via said patterned lines. There is also a plurality of radiation chips electrically connected to selected ones of said pads. Preferably the device is wrapped around a core member, that may be a wire, such that the assembly is suitable for the insertion into a living body for the controlled administration of radiation at a therapy location.