Disclosed is an apparatus that includes a modifiable fiber structure adapted to operate in at least two configurations such that in a sideways-firing configuration the fiber structure is adapted to emit radiation in a substantially sideways direction relative to a longitudinal axis of the fiber structure, and in another, axial-firing, configuration the fiber structure is adapted to emit radiation in a substantially axial direction relative to the longitudinal axis of the fiber structure. Also disclosed is another apparatus that includes a guide tube disposed within a scope, the guide tube configured to be advanced to a position near an area to be treated so that the scope can be advanced along the guide tube to the position near the area to be treated. The guide tube is further configured to receive a treatment instrument to perform a treatment procedure on the area to be treated.
