Technetium99mSulfurColloidChecker

Utility description: Tc-99m Sulfur Colloid

Tc-99m Sulfur Colloid Quality Checker — Technetium-99m Sulfur Colloid

ℹ️  Utility checks critical parameters of Tc-99m Sulfur Colloid:
    • Radiochemical purity (≥92%)
    • Particle size (depends on application: liver/lymph)
    • Boiling time (3-6 min) — CRITICAL!
    • Free pertechnetate (≤5%)
    • pH, endotoxins, sterility

⚠️  CRITICAL: Insufficient boiling leads to absence of colloid.
    Particles too large (>1.5 μm) get stuck in lung capillaries!

Usage:
  Technetium99mSulfurColloidChecker.exe                            → demo mode (console output)
  Technetium99mSulfurColloidChecker.exe input.csv output.json      → evaluate your data

Input format:
BatchNumber,TotalActivityMBq,RadiochemicalPurityPercent,FreePertechnetatePercent,ParticleSizeMicrons,pH,EndotoxinsEU,SterilityTest,BoilingTimeMin,ProductType

Example (sterility: 0=sterile, 1=contaminated):
  TC99M-SC-2026-110,150.0,98.0,1.5,0.3,5.5,10.0,0,4.0,LiverSpleen

Supported product types:
• LiverSpleen — liver, spleen, bone marrow imaging
• Lymphoscintigraphy — lymphoscintigraphy (sentinel node biopsy)
• GastricEmptying — gastric emptying study

— WHY IS THIS NEEDED?
Tc-99m Sulfur Colloid is a suspension of insoluble sulfur particles labeled with technetium:
• Liver/Spleen: Particles sized 0.1–1.0 μm are phagocytized by Kupffer cells of the liver and macrophages of the spleen. Used to assess organ structure, detect focal lesions, portal hypertension.
• Lymphoscintigraphy: Very small particles (<0.1 μm, often filtered) are injected interstitially and drain to lymph nodes. Gold standard for sentinel lymph node biopsy in breast cancer and melanoma.
• Stomach: Not absorbed, used as a solid food marker to assess gastric motility.

⚠️  CRITICAL:
• Radiochemical purity ≥92% — Low RCP means presence of free pertechnetate, which accumulates in thyroid and stomach, creating unwanted background.
• Particle Size — THE MOST IMPORTANT PARAMETER determining biodistribution.
  - For liver/spleen: 0.1–1.0 μm.
  - For lymph nodes: <0.1 μm (nanocolloid).
  - If particles are >1.5 μm (aggregates due to over-boiling or preparation errors), they get stuck in lung capillaries, causing microembolism and making liver image non-diagnostic.
• Preparation Process (Boiling) — Colloid formation reaction requires boiling for 3-5 minutes. Without this, particles do not form or are unstable.
• Free pertechnetate ≤5% — Artifacts in neck and chest area.
• pH 4.0–7.5, Endotoxins ≤175 EU/vial, Sterility — standard requirements.

Key features:
• Control of particle size depending on clinical task
• Control of boiling time (critical for synthesis)
• Assessment of suitability for different study types (liver, lymph, stomach)

Critical parameters:
• Radiochemical purity: ≥92.0%
• Free pertechnetate: ≤5.0%
• Particle size:
  - Liver/Spleen: 0.1–1.0 μm
  - Lymph: <0.1 μm
• Boiling time: 3.0–6.0 minutes
• pH: 4.0–7.5
• Endotoxins: ≤175 EU/vial
• Sterility: no microbial growth

💡 Usage tips:
1. Membrane filtration or microscopy is used to control particle size.
2. Strictly observe boiling time. Use water bath.
3. For lymphoscintigraphy, the prepared drug is often passed through a 0.22 μm or 0.45 μm filter to remove large aggregates.
4. The drug is stable for several hours, but best used fresh.

⚠️ Note: Sulfur Colloid is one of the few drugs where particle size is the key success factor. Error in size (particles too large) changes the target organ from liver to lungs, which is a serious quality incident.