Radioactive decay
Corrects radiopharmaceutical activity to administration or measurement time using calibrated activity and physical half-life.
Calculate with transparency
Check the population, units and version. The result shows the formula or classification; it does not make an automatic treatment decision.
Preparing the form…
- Check the method
- Enter the data
- Check the result
Method · Limits of application
Exponential physical decay; six NUBASE2020 half-lives compared and rounded; 68Ga 67.8 min; 177Lu 6.64 days; activity in the original unit.
This model calculates only the exponential physical decay of a single radionuclide, with initial and final activity in the same unit and time consistent with the half-life. It does not include biological elimination, effective half-life, ingrowth from parent radionuclides or absorbed dose. The six presets were compared with the corresponding NUBASE2020 entries and rounded: 99mTc 6.01 h; 18F 109.7 min; 131I 8.02 days; 123I 13.2 h; 68Ga 67.8 min; 177Lu 6.64 days. Identify the nuclear state. Preset rounding does not incorporate the evaluation’s uncertainties and does not certify metrological data or patient dosimetry.
Conditions of use
Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.
Documented parameters
- Radionuclide
- Initial activity (MBq or mCi) · MBq/mCi
- Elapsed time
- Time unit
4/4 reference cases checked. Numerical tests are not clinical validation.
Relationship with cancer research
Support for research — context required
A physical model of radioactive activity. It supports methodological preparation in nuclear medicine; it does not determine absorbed dose, treatment or biological effect.
Applications: Pharmacology