Medical Isotope Decay Calculator

Visualize how radiopharmaceutical activity decays over time — the physics that drives supply-chain decisions in nuclear medicine.

F-18

Fluorine-18 (FDG-PET)

t½ = 110 min

Tc-99m

Technetium-99m (SPECT)

t½ = 6.0 h

Y-90

Yttrium-90 (Radioembolization)

t½ = 64.0 h

Lu-177

Lutetium-177 (PSMA Therapy)

t½ = 6.7 d

Ac-225

Actinium-225 (Alpha Therapy)

t½ = 10.0 d

Time since calibration: 0 h

Remaining Activity: 100%

Number of half-lives elapsed 0.00

Activity if starting at 1 GBq 1.00 GBq

Practical use window remaining

Data from National Nuclear Data Center (NNDC) isotopic decay parameters. For nuclear medicine logistics planning — not a clinical dosage tool.