Systems and methods for rotating shield brachytherapy. In an aspect, some of the systems and methods can be used to facilitate shield selection for use in rotating shield brachytherapy. In an aspect, the invention is a shielded needle or catheter system with a rotational controller for delivering radioisotope-based interstitial rotating shield brachytherapy (I-RSBT). In an aspect, the catheter system can utilize paddle-based RSBT. Further provided are methods and systems for helical RSBT.
