Iodine123FPCTQualityChecker

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of Iodine123FPCTQualityChecker for Iodine-123 FP-CIT.

Domain limits and critical parameters

• ℹ️ Utility checks critical parameters of the radiopharmaceutical for dopamine transporter imaging:
• • Radiochemical purity (≥95%)
• • Free Iodine-123 impurity (≤5%)
• • Radionuclidic impurity Iodine-124 (≤0.3%) — CRITICAL!
• • Radionuclidic impurity Iodine-125 (≤0.1%)
• • Specific activity (≥100 GBq/μmol)
• • pH, endotoxins, sterility, residual ethanol
• ⚠️ CRITICAL: I-124 impurity >0.3% is unacceptable! I-124 emits positrons and high-energy gamma rays, significantly increasing patient dose and degrading image quality (noise).
• Free iodine accumulates in the thyroid and stomach, creating artifacts.
• BatchNumber,RadiochemicalPurityPercent,FreeIodine123Percent,RadionuclidicPurityI124Percent,RadionuclidicPurityI125Percent,SpecificActivityGBqPerUmol,pH,EndotoxinsEU,SterilityTest,EthanolPercent,AppearanceScore
• Example (sterility: 0=sterile, 1=contaminated, appearance: 0=normal):
• ⚠️ CRITICAL:
• • Radiochemical purity ≥95% — ensures specific binding to DAT.
• • Free Iodine-123 ≤5% — requires thyroid blocking with potassium iodide prior to administration if impurity is high.

URS — User Requirements Specification

input.csv contract

BatchNumber,RadiochemicalPurityPercent,FreeIodine123Percent,RadionuclidicPurityI124Percent,RadionuclidicPurityI125Percent,SpecificActivityGBqPerUmol,pH,EndotoxinsEU,SterilityTest,EthanolPercent,AppearanceScore
I123-FPCT-2026-001,98.5,1.0,0.1,0.05,150.0,7.0,40.0,0,5.0,0
I123-FPCT-2026-002,94.0,4.0,0.5,0.08,120.0,7.2,50.0,0,6.0,0

FS — Functional Specification

Example output.json

{
  "utilityId": "iodine123-fpct-quality-checker",
  "api": "Iodine-123 FP-CIT",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "I123-FPCT-2026-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadiochemicalPurityPercent",
      "value": "98.5",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "FreeIodine123Percent",
      "value": "1.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadionuclidicPurityI124Percent",
      "value": "0.1",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadionuclidicPurityI125Percent",
      "value": "0.05",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "SpecificActivityGBqPerUmol",
      "value": "150.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "pH",
      "value": "7.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "EndotoxinsEU",
      "value": "40.0",
      "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.