Abstract: A radioactive source ribbon assembly may be reusably utilized in conjunction with a delivery sheath or catheter for delivering therapeutic dosages of ionizing radiation to various anatomical regions. The radioactive source ribbon assembly comprises an outer jacket formed from or coated with a lubricious coating for insertion into the delivery sheath or catheter. The assembly also comprises a radiation resistant sleeve formed from a braided structure which encapsulates a radioactive source and core. The braided structure is the primary axial load bearing member of the assembly and functions as such without sacrificing assembly flexibility.