Tc99mHMPAOQualityChecker

Utility description: Tc-99m HMPAO

Tc-99m HMPAO Quality Checker — Technetium-99m HMPAO for Brain SPECT Perfusion

ℹ️  Utility checks critical parameters of Tc-99m HMPAO:
    • Radiochemical purity of lipophilic complex (≥80%)
    • Secondary complex (≤15%)
    • Free pertechnetate (≤5%)
    • Colloidal technetium (≤5%)
    • SHELF LIFE: Use within 30 minutes!
    • pH, endotoxins, sterility

⚠️  CRITICAL: HMPAO is extremely unstable. After 30 minutes, most of the drug
    converts to a secondary hydrophilic complex that DOES NOT CROSS the blood-brain barrier.

Usage:
  Tc99mHMPAOQualityChecker.exe                            → demo mode (console output)
  Tc99mHMPAOQualityChecker.exe input.csv output.json      → evaluate your data

Input format:
BatchNumber,TotalActivityMBq,RadiochemicalPurityPercent,SecondaryComplexPercent,FreePertechnetatePercent,ReducedHydrolyzedTcPercent,pH,EndotoxinsEU,SterilityTest,TimeSinceReconstitutionMin,ProductType

Example (sterility: 0=sterile, 1=contaminated):
  TC99M-HMPAO-2026-015,740.0,85.0,10.0,3.0,2.0,7.4,20.0,0,15,CerebralPerfusion

Supported product types:
• CerebralPerfusion — cerebral perfusion (stroke, dementia)

— WHY IS THIS NEEDED?
Tc-99m HMPAO (Hexamethylpropyleneamine oxime, trade name Ceretec®) is the gold standard for SPECT diagnosis of cerebral blood flow:
• Lipophilic neutral molecule easily crosses the blood-brain barrier (BBB)
• Inside brain cells, it converts to a hydrophilic complex and gets "trapped" (retention mechanism)
• Distribution in the brain reflects regional blood flow
• Used in diagnosis of stroke, Alzheimer's disease, epilepsy

⚠️  CRITICAL:
• Radiochemical Purity (Lipophilic complex) ≥80% — ONLY the lipophilic form crosses the BBB. If purity is lower, image quality will be poor, and dose to peripheral organs will increase.
• Secondary complex ≤15% — HMPAO spontaneously degrades into a secondary hydrophilic complex even in the vial. This complex DOES NOT cross the BBB and is rapidly excreted by kidneys. Its accumulation leads to poor signal-to-noise ratio.
• TEMPORAL STABILITY (≤30 min) — THE MOST IMPORTANT PARAMETER. The drug must be administered to the patient within 30 minutes after adding pertechnetate. After 30 minutes, the fraction of lipophilic complex falls below acceptable levels.
• Free pertechnetate ≤5% — Accumulates in thyroid gland, salivary glands, and stomach, creating artifacts in neck/head images.
• Reduced/Hydrolyzed Tc ≤5% — Colloid accumulating in liver and spleen.
• pH 7.0–8.5, Endotoxins ≤175 EU/vial, Sterility — standard requirements.

Key features:
• Control of drug shelf life (Time Since Reconstitution)
• Separation of technetium forms: lipophilic (target), secondary (degradation), free, colloidal
• Assessment of suitability for neuroimaging

Critical parameters:
• Lipophilic complex (RCP): ≥80.0%
• Secondary complex: ≤15.0%
• Free pertechnetate: ≤5.0%
• Colloidal Tc: ≤5.0%
• Time since reconstitution: ≤30 minutes (STRICT!)
• pH: 7.0–8.5
• Endotoxins: ≤175 EU/vial
• Sterility: no microbial growth

💡 Usage tips:
1. To determine RCP, TLC with two solvent systems is used:
   - System 1 (MEK): Separates free pertechnetate (moves) from complexes and colloid (origin).
   - System 2 (Saline): Separates hydrophilic forms (secondary complex + free Tc, move) from lipophilic complex and colloid (origin).
   - Calculation of lipophilic complex requires combining data.
2. Always record the exact time of reconstitution (addition of Tc-99m).
3. If more than 30 minutes have passed — DISCARD the drug. No tests will save image quality.
4. Use fresh generator eluate (age less than 4 hours) for better labeling yield.

⚠️ Note: HMPAO is one of the most "capricious" radiopharmaceuticals due to its instability. Success of the study depends 90% on compliance with the time schedule ("30-minute rule"). Violation of this rule makes the study diagnostically worthless.