A removable implant having a radiation shield adapted to reduce radiation exposure to one or more secondary radio-sensitive tissues during breast cancer radiation therapy is provided herein, the implant including: a radiation-absorbing core adapted to absorb at least a portion of cardiac impact zone radiation when compared to a control, wherein the radiation-absorbing core comprises: a flexible solid polymer； and a plurality of radiation-absorbing members dispersed throughout the flexible solid polymer, wherein the radiation-absorbing core comprises a plurality of zones, each of said zones comprising a distinct capacity for radiation absorption, wherein capacity for radiation absorption is proportional to a sensitivity of the secondary radio-sensitive tissues to radiation, such a zone that shields tissue comparatively more sensitive to radiation comprises a zone having a comparatively higher capacity for radiation absorption, and a zone that shields tissue comparatively less sensitive to radiation comprises a zone having a comparatively lower capacity for radiation absorption. Also provided is an implant having a breast tissue expander disposed on a top face of the flexible casing of the implant. Methods of use of the described implants are also provided herein.
