PhotonsRadiation DosageRadiation, IonizingRadiation InjuriesDose-Response Relationship, RadiationRadiationRadiation ToleranceRadiation ProtectionRadiation MonitoringRadiation OncologyTomography, Emission-Computed, Single-PhotonRadiometryCosmic RadiationRadiation Injuries, ExperimentalRadiotherapy DosageRadiotherapyRadiation PneumonitisNeoplasms, Radiation-InducedGamma Rays