Devices and methods are disclosed for treatment to tissue surrounding a body cavity or other intracorporeal site, such as after removal of tissue, e.g. cancer. Such a device includes a treatment location on a distal portion of the device with one or more radiation shielding components that partially encircle a radiation source at the treatment location to control emitted radiation from the radiation source. The device minimizes radiation damage to healthy tissue surrounding the body cavity or other site while irradiating tissue not shielded by the radiation shielding components. A device embodying features of the invention can include a sealing member at a location on a shaft of the device proximal to a treatment location to seal the passageway leading to the body cavity.
