Technetium99mECDQualityChecker

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of Technetium99mECDQualityChecker for Tc-99m ECD.

Domain limits and critical parameters

• ℹ️ Utility checks critical parameters of Tc-99m ECD:
• • Radiochemical purity (≥95%)
• • Free pertechnetate (≤2%)
• • Colloidal technetium (≤3%)
• • pH, endotoxins, sterility
• ⚠️ CRITICAL: ECD requires reconstitution with alkaline solution before adding technetium.
• BatchNumber,TotalActivityMBq,RadiochemicalPurityPercent,FreePertechnetatePercent,ReducedHydrolyzedTcPercent,pH,EndotoxinsEU,SterilityTest,TimeSinceReconstitutionMin,ProductType
• Example (sterility: 0=sterile, 1=contaminated):
• ⚠️ CRITICAL:
• • Radiochemical purity ≥95% — ONLY the lipophilic form crosses the BBB. Low RCP leads to poor signal-to-noise ratio.
• • Free pertechnetate ≤2% — Accumulates in choroid plexuses of brain ventricles, creating artifacts ("hot" ventricles) that can mask pathology or mimic it. Also accumulates in thyroid and stomach.
• • Reduced/Hydrolyzed Tc ≤3% — Colloid accumulating in liver and spleen.
• • TEMPORAL STABILITY (≤4 hours) — After adding alkaline solution and pertechnetate, the drug is stable for 4 hours at room temperature. This is an advantage over HMPAO.
• • pH 7.0–8.5, Endotoxins ≤175 EU/vial, Sterility — standard requirements.

URS — User Requirements Specification

input.csv contract

BatchNumber,TotalActivityMBq,RadiochemicalPurityPercent,FreePertechnetatePercent,ReducedHydrolyzedTcPercent,pH,EndotoxinsEU,SterilityTest,TimeSinceReconstitutionMin,ProductType
TC99M-ECD-2026-060,740.0,98.0,1.0,1.0,7.4,15.0,0,30,CerebralPerfusion
TC99M-ECD-OLD-061,700.0,90.0,5.0,5.0,7.2,20.0,0,300,CerebralPerfusion
TC99M-ECD-FAIL-062,720.0,94.0,3.0,3.0,7.8,10.0,0,20,CerebralPerfusion

FS — Functional Specification

Example output.json

{
  "utilityId": "technetium99m-ecd-quality-checker",
  "api": "Tc-99m ECD",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "TC99M-ECD-2026-060",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "TotalActivityMBq",
      "value": "740.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadiochemicalPurityPercent",
      "value": "98.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "FreePertechnetatePercent",
      "value": "1.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "ReducedHydrolyzedTcPercent",
      "value": "1.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "pH",
      "value": "7.4",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "EndotoxinsEU",
      "value": "15.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "SterilityTest",
      "value": "0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    }
  ],
  "criticalFindings": []
}

OQ/PQ test scenarios

QA/QC and change control

• Do not rename columns without updating the validator and test set.
• Retain input.csv, output.json, executable version and checksum.
• Before production use, perform IQ/OQ/PQ or equivalent CSV/CSA verification.
• Critical radiopharmaceutical limits must be verified against the approved specification and local SOPs.