Why a Post Implant CT? As you left Chicago Prostate Cancer Center after your implant, you were given a prescription for a CT scan, along with specific instructions to be given to the technologist who will perform the scan. This CT study will allow our physics team to calculate the actual radiation dose to your prostate and surrounding structures. As soon as we receive copies of the CT films, the Radiation Oncologist who performed your implant will review the films and have the physics team compute the radiation dose to the prostate. This information will remain in your chart as part of our permanent records. IMPORTANT: As you know, radioactive seeds have been placed into your prostate. Be sure to notify any physician who examines you of this. Under no circumstances should you have a digital rectal examination for 6 months after your implant, for two reasons: Exposure of the examining finger to radiation; Disturbance or movement of the seeds, causing a disruption of the radiation dose. This dose was carefully calculated and placed, and disruption of the seed could have an adverse effect on your treatment.