Once released, the energy stops - there is no exit dose and no additional radiation unlike X-ray beams and gamma knife rays.

During the struggle with police Young abuses the policemen because he drops his "Exit Dose" of thallium which he intended to use to commit suicide should he be caught.

The ability to collect "exit dose" on CT detectors further permits daily verification of radiation dose-delivery, and the serial availability of both changes in tumor anatomy and variations in dose-deposition permits "adaption" of radiotherapy treatment plans.