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☢️ Radionuclide Decay Calculator

UsePost-injection remaining activity, elution hold time, decay-correction checks, teaching. Physical decay only.

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SourceICRP / chart of the nuclides — physical half-lives (Tc-99m, F-18, I-131, etc.)

Runs locally in your browser (no PHI uploaded). For licensed clinicians — not a substitute for clinical judgement.
Stored on this device for revisit reminders

This-shift next steps

After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.

Scene next step
📋nm nuclearOpen scene pack →
Related scores
Score + version; reference only — not a substitute for care · no HIS write

Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.

Methodology · worked example, guidelines & full notes
Clinical takeaway

Presets use commonly cited physical half-lives.

When to use

Post-injection remaining activity, elution hold time, decay-correction checks, teaching. Physical decay only.

How it works

A = A0 · e^(−λt), λ = ln2 / T½. Half-lives converted to hours. 1 mCi = 37 MBq.

Key points

  • Presets use commonly cited physical half-lives.
  • Optional time-to-target %.
  • No biological clearance.

References

  • ICRP / chart of the nuclides — physical half-lives (Tc-99m, F-18, I-131, etc.)

Worked calculation

The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.

NuclideLu-177 (6.65 d)
Initial activity A010
Activity unitmCi
Elapsed time (hours)6 h
Extra minutes (optional)0 min
Target % remaining (optional)10 %

→Remaining activity9.7428mCi

  • % remaining：97.43 %
  • Elapsed half-lives：0.038
  • Other unit：360.483 MBq
NuclideTc-99m (6.01 h)
Initial activity A010
Activity unitmCi
Elapsed time (hours)6 h
Extra minutes (optional)0 min
Target % remaining (optional)10 %

→Remaining activity5.0058mCi

  • % remaining：50.06 %
  • Elapsed half-lives：0.998
  • Other unit：185.2135 MBq
Verification & sources · governance
FAQ

Frequently asked questions

What are the limits and cautions when using Radionuclide Decay Calculator?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
Does Radionuclide Decay Calculator upload patient data? Where is it calculated?
Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
How is Radionuclide Decay Calculator calculated in practice? Can you show a worked example?
Inputs: Nuclide Lu-177 (6.65 d), Initial activity A0 10, Activity unit mCi, Elapsed time (hours) 6 h, Extra minutes (optional) 0 min, Target % remaining (optional) 10 % → Result: Remaining activity 9.7428 mCi（% remaining: 97.43 %, Elapsed half-lives: 0.038, Other unit: 360.483 MBq） Inputs: Nuclide Tc-99m (6.01 h), Initial activity A0 10, Activity unit mCi, Elapsed time (hours) 6 h, Extra minutes (optional) 0 min, Target % remaining (optional) 10 % → Result: Remaining activity 5.0058 mCi（% remaining: 50.06 %, Elapsed half-lives: 0.998, Other unit: 185.2135 MBq）
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