Abstract: According to the invention there is provided a radiation source for use in endovascular radiation treatment which comprises one or more and preferably at least two treating elements or seeds comprising a radiation emitting element and means for containment of said radiation emitting element which radiation source is characterized in that said seeds comprised in an elongated container having at least one deflection site. There is further provided an apparatus for endovascular radiation treatment comprising an elongated catheter, optionally a guide wire and the radiation source as defined above.