Fluorine18FLTQualityChecker

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of Fluorine18FLTQualityChecker for Fluorine-18 FLT.

Domain limits and critical parameters

• ℹ️ Utility checks critical parameters of [18F]FLT (3'-deoxy-3'-[18F]fluorothymidine):
• • Radionuclidic purity (≥99.9%)
• • Radiochemical purity (≥95%)
• • Free Fluoride-18 impurity (≤5.0%)
• • Precursor/Cold FLT impurity (≤2.0%)
• • Specific activity (≥50 GBq/μmol)
• • Residual solvents (ethanol), pH, endotoxins, sterility
• ⚠️ CRITICAL: Free Fluoride-18 >5.0% → accumulation in bones, risk of false positives in bone metastasis detection!
• BatchNumber,RadionuclidicPurityPercent,RadiochemicalPurityPercent,FreeFluoridePercent,PrecursorImpurityPercent,pH,EndotoxinsEU,SterilityTest,HeavyMetalsPPM,ResidualEthanolPercent,SpecificActivityGBqPerUmol
• Example (sterility: 0=sterile, 1=contaminated):
• ⚠️ CRITICAL:
• • Radiochemical purity ≥95% — ensures specific phosphorylation by TK1 enzyme inside cells
• • Free Fluoride ≤5.0% — [18F]fluoride is actively taken up by bone tissue. When assessing proliferation in bone marrow or bone metastases, this creates critical background
• • Specific activity ≥50 GBq/μmol — necessary to minimize competitive inhibition of TK1 enzyme by cold thymidine/FLT

URS — User Requirements Specification

input.csv contract

BatchNumber,RadionuclidicPurityPercent,RadiochemicalPurityPercent,FreeFluoridePercent,PrecursorImpurityPercent,pH,EndotoxinsEU,SterilityTest,HeavyMetalsPPM,ResidualEthanolPercent,SpecificActivityGBqPerUmol
F18-FLT-2026-001,99.99,98.0,1.5,0.5,7.0,30.0,0,2,5.0,120.0
F18-FLT-2026-002,99.95,94.0,6.5,1.0,6.8,100.0,0,5,8.0,40.0
F18-FLT-2026-003,99.98,99.0,0.5,0.2,7.2,10.0,0,1,2.0,200.0

FS — Functional Specification

Example output.json

{
  "utilityId": "fluorine18-flt-quality-checker",
  "api": "Fluorine-18 FLT",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "F18-FLT-2026-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadionuclidicPurityPercent",
      "value": "99.99",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadiochemicalPurityPercent",
      "value": "98.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "FreeFluoridePercent",
      "value": "1.5",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "PrecursorImpurityPercent",
      "value": "0.5",
      "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": "30.0",
      "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.