Abstract: The invention relates to a radially expandable multi-layer tubular structure which is intended to be used as a stent and to the production method thereof. The inventive structure comprises an outer layer (1) and an inner layer (2) which are solidly connected to one another. One of the aforementioned layers (2) is provided with hollow channels (3) through the thickness thereof while the other layer is provided with perforations (4). Said channels (3) can be used to alter the mechanical properties of the stent and to house a medicament for the local treatment of the vessel in which the stent is disposed.

Abstract: A system for intravascular ionizing radiation therapy including a radiation device and a guide wire having radiopaque markers to facilitate precise repositioning of the radiation source along the length of the treatment site. The radiopaque markers are separated by a distance L, which corresponds to the distance between the 50% dose points in the dose fall-off regions. This produces partial dose overlap when the radioactive source is positioned in tandem adjacent each radiopaque marker. Preferably, only the dose fall-off regions overlap thereby providing more uniform and complete radiation exposure along the length of the treatment site.

Abstract: A filament for irradiating a living body has a core material capable of irradiating radioactive radiation clad in a tubular casing of protective material different from the material forming the core. The materials forming the core and casing have a purity not less than 99.5 atomic percent and a grain size not exceeding 30 .mu.m and the outer diameter of the filament is not less than 80 .mu.m.