GeneratorElutionPredictor

Generator Elution Predictor — Generator elution activity predictor

ℹ️  Utility calculates PREDICTED daughter nuclide activity in generator eluate:
    • Accounts for parent nuclide decay since calibration
    • Accounts for daughter nuclide ingrowth between elutions
    • Applies elution efficiency to calculate activity in eluate
    • Estimates number of possible patient doses

⚠️  IMPORTANT: Result is a PREDICTION and does NOT replace activity measurement
    before clinical use. Used for production planning and assessment of activity
    sufficiency for scheduled studies.

Usage:
  GeneratorElutionPredictor.exe                            → demo mode (console output)
  GeneratorElutionPredictor.exe input.csv output.json      → calculate with your data

Input format:
BatchNumber,GeneratorType,GeneratorCalibrationActivityMBq,CalibrationDateTime,LastElutionDateTime,NextElutionDateTime,ElutionEfficiencyPercent,DosePerPatientMBq

Examples:
  TC99M-GEN-2026-001,Mo99-Tc99m,30000.0,2026-03-17T08:00:00,2026-03-18T08:00:00,2026-03-19T08:00:00,80.0,750.0
  GA68-GEN-2026-001,Ge68-Ga68,1850.0,2026-03-01T08:00:00,2026-03-18T08:00:00,2026-03-18T14:00:00,60.0,200.0
  RB82-GEN-2026-001,Sr82-Rb82,3700.0,2026-03-10T08:00:00,2026-03-18T08:00:00,2026-03-18T09:00:00,90.0,1500.0

— WHY IS THIS NEEDED?
Generator elution planning is critical in radiopharmacy:
• For diagnostic generators (Mo-99/Tc-99m) — ensuring sufficient activity for all
  scheduled studies during the day
• For therapeutic/PET generators (Ge-68/Ga-68, Sr-82/Rb-82) — optimizing elution timing
  for maximum activity with minimal losses
• For inventory management — deciding when to order a new generator
• For documentation — activity prediction for reporting and audits

⚠️ CRITICAL:
• Utility uses PHYSICAL decay model accounting for transient equilibrium
• Formula: A_d(t) = A_p(0) × [λ_d / (λ_d - λ_p)] × [1 - e^(-(λ_d - λ_p)×t)] × e^(-λ_p×t)
• Requires knowledge of PARENT nuclide activity at generator calibration
  (provided in generator certificate by manufacturer)
• Elution efficiency varies by generator type and method:
  — Mo-99/Tc-99m: 70-90% (typically 80%)
  — Ge-68/Ga-68: 50-70% (typically 60%)
  — Sr-82/Rb-82: 85-95% (typically 90%)
• Result is a PREDICTION — actual activity must be measured with dose calibrator
  before clinical use!

Key features:
• Support for 3 major generator types with accurate half-lives
• Automatic daughter nuclide ingrowth time calculation
• Parent nuclide decay since calibration accounted for
• Patient dose count calculation
• Result categorization: EXCELLENT / ADEQUATE / MARGINAL / INSUFFICIENT
• Optional parameters with reasonable defaults
• Demo mode with clinically relevant examples for all generator types

Supported generators:
• Mo-99/Tc-99m: T½(Mo-99)=66 h, T½(Tc-99m)=6.01 h, efficiency=80%, dose=750 MBq
  Use: bone, cardiac, renal scintigraphy
• Ge-68/Ga-68: T½(Ge-68)=6480 h (271 days), T½(Ga-68)=1.13 h, efficiency=60%, dose=200 MBq
  Use: NET, prostate cancer PET
• Sr-82/Rb-82: T½(Sr-82)=605 h (25.2 days), T½(Rb-82)=0.0212 h (1.27 min), efficiency=90%, dose=1500 MBq
  Use: cardiac PET perfusion

💡 Usage tips:
1. Always use PARENT nuclide activity from generator certificate
   (do not confuse with activity in first eluate!)
2. For Mo-99/Tc-99m optimal time between elutions is 24 hours
3. For Ge-68/Ga-68 maximum activity reached 10-12 hours after elution
4. For Sr-82/Rb-82 elution possible every 10 minutes (short daughter half-life)
5. For INSUFFICIENT prediction — increase ingrowth time or order new generator
6. Document prediction before elution for audits

⚠️ Limitations:
• Does not account for column aging (decreasing efficiency over time)
• Does not account for generator storage temperature conditions
• Does not replace activity measurement before clinical use
• Assumes ideal elution (real-world variations ±10% possible)

Data sources:
• IAEA Technical Reports Series No. 466 (2009) — Radiopharmaceuticals for Positron Emission Tomography
• USP General Chapter <825> — Radiopharmaceuticals for Positron Emission Tomography
• Manufacturer specifications for commercial generators (Curium, IThemba LABS, etc.)
• Journal of Nuclear Medicine Technology — Generator elution efficiency studies