Tc99mRenalDosimetryCalculator

Utility description: Tc-99m Renal Dosimetry Calculator

Tc-99m Renal Dosimetry Calculator — Radiation dose calculation for renal scintigraphy

ℹ️  Utility calculates absorbed doses based on MIRD model:
    • Kidney Absorbed Dose
    • Bladder Wall Dose
    • Effective Whole Body Dose
    • Consideration of biological half-life and voiding frequency

⚠️  CRITICAL: Frequent bladder voiding reduces dose by 30-50%!
    For DMSA, kidney dose is significantly higher due to cortical fixation.
    Follow ALARA principle (As Low As Reasonably Achievable).

Usage:
  Tc99mRenalDosimetryCalculator.exe                            → demo mode (console output)
  Tc99mRenalDosimetryCalculator.exe input.csv output.json      → evaluate your data

Input format:
PatientID,Radiopharmaceutical,InjectedActivityMBq,PatientWeightKg,PatientAgeYears,BiologicalHalfLifeHours,BladderVoidingIntervalHours,KidneyMassGrams

Example:
  PAT-DOS-001,MAG3,200.0,70.0,45.0,2.5,2.0,150.0

— WHY IS THIS NEEDED?
Patient radiation safety is a priority in nuclear medicine.
• Different drugs (MAG3, DTPA, DMSA) have different biodistribution and thus different dose profiles.
• Kidneys and bladder are target organs receiving the highest radiation dose.
• Calculation of effective half-life allows accurate assessment of isotope residence time in the body.
• Bladder voiding frequency is the only parameter patient can control to reduce dose.

⚠️  CRITICAL:
• DMSA gives the highest kidney dose (up to 0.065 mGy/MBq) due to long fixation in cortical layer.
• MAG3 and DTPA give lower kidney dose but higher bladder dose due to rapid excretion.
• In children, dose coefficients are higher due to smaller organ sizes and body mass.
• ALARA principle requires using minimum necessary activity for diagnostic image quality.

Key features:
• Calculation of effective half-life (Teff) based on physical and biological T½.
• Use of MIRD S-factors for absorbed dose estimation.
• Consideration of bladder voiding interval (critical for DTPA/MAG3).
• Comparison with reference dose load levels.
• Support for pediatric calculations (via weight and age).

Critical parameters:
• Kidney dose: < 0.1 mGy/MBq (for MAG3/DTPA)
• Bladder dose: < 0.1 mGy/MBq (with 2h voiding)
• Effective dose: minimized according to patient weight

💡 Usage tips:
1. Encourage patients to void bladder frequently after the study.
2. For children, use pediatric activity protocols (e.g., EANM Paediatric Dosage Card).
3. When using DMSA, consider that kidney dose accumulates over first 24 hours.
4. Always document injected activity and calculated dose in medical record.
5. For pregnant patients, calculation must be done with extreme caution (fetal dose consideration).

⚠️ Note: This utility translates abstract "Megabecquerels" into understandable medical risks (mSv and mGy). It helps physician justify drug and activity choice, balancing between diagnostic quality and patient safety.