Abstract: This invention proposes a robotic applicator device to be deployed internally to a patient having a capsule (also referred to as a cassette) and aperture with a means of alternately occluding and exposing a radioactive source through the aperture. The capsule and aperture will be integrated with a surgical robot to create a robotic IORT (intra-operative radiation therapy) applicator device as more fully described below. The capsule, radiation source, and IORT applicator arm would be integrated to enable a physician, physicist or technician to interactively internally view and select tissue for exposure to ionizing radiation in sufficient quantities to deliver therapeutic radiation doses to tissue. Via the robotic manipulation device, the physician and physicist would remotely apply radiation to not only the tissue to be exposed, but also control the length of time of the exposure.