Ac225TargetedAlphaTherapyQC

Ac-225 Targeted Alpha Therapy QC

api radiopharmaceuticals nuclear-medicine ac-225 targeted-alpha-therapy theranostics oncology

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Ac-225 Targeted Alpha Therapy QC — Quality control of Actinium-225 targeted alpha therapy

ℹ️ Utility checks critical parameters of Ac-225 radioligands:

Radiochemical purity (≥95%)
Free Ac-225 (≤2%)
Daughter nuclides (<1%) — recoil effect control!
Ac-227 impurity (<0.001%) — CRITICAL!
Specific activity, pH, endotoxins, sterility

⚠️ CRITICAL: Ac-227 (T½=21.8 years) creates lifelong radiation burden!

Alpha particles have high LET. Any chelation error leads to healthy tissue destruction.

Highest radiochemical stability of complex is required.

Usage

Ac225TargetedAlphaTherapyQC.exe → demo mode (console output)

Ac225TargetedAlphaTherapyQC.exe input.csv output.json → evaluate your data

Input format

BatchNumber,RadiochemicalPurityPercent,FreeAc225Percent,DaughterNuclidesPercent,SpecificActivityGBq_per_mg,pH,EndotoxinsEU_per_mL,SterilityTest,ActivityMBq,RadionuclidicPurityPercent,Ac227ImpurityPercent

Example

AC225-PSMA-2026-001,98.5,1.0,0.5,40.0,5.5,10.0,0,100.0,99.99,0.0005

— WHY IS THIS NEEDED?

Actinium-225 is one of the most promising isotopes for targeted alpha therapy (TAT).

Emits 4 alpha particles in decay chain, providing powerful local impact on tumor.
However, alpha particles have very short range (50-100 μm) and high linear energy transfer (LET).
If complex decays in blood, free Ac-225 and its daughter nuclides (Fr-221, Bi-213) damage kidneys and bone marrow.
Ac-227 impurity (half-life 21.8 years) is unacceptable as it remains in patient's body for decades.

⚠️ CRITICAL:

Radiochemical purity ≥95% — guarantee that alpha emitter is delivered exactly to target.
Free Ac-225 ≤2% — minimization of accumulation in liver and bones.
Daughter nuclides <1% — control of "recoil effect" when nucleus escapes chelator during decay.
Ac-227 impurity <0.001% — strictest regulatory requirement due to long-term toxicity.
Specific activity must be high to avoid receptor saturation by "cold" metal.
pH 4.5-7.5 — for biocompatibility.
Endotoxins <175 EU/mL — standard for parenteral drugs.
Sterility — MANDATORY.

Key features

Strict radionuclidic purity control with focus on Ac-227.
Complex stability assessment against recoil effect.
Specific activity check for effective targeting.
Compliance with GMP requirements for alpha emitters.
Comprehensive safety check (endotoxins, sterility, pH).

Critical parameters

Radiochemical purity: ≥95.0%
Free Ac-225: ≤2.0%
Daughter nuclides: <1.0%
Specific activity: ≥20.0 GBq/mg
Radionuclidic purity: ≥99.9%
Ac-227 impurity: <0.001%
pH: 4.5–7.5
Endotoxins: <175 EU/mL
Sterility: no growth

💡 Usage tips:

1. Radiochemical purity determined by TLC or HPLC with alpha detection.

2. Ac-227 impurity controlled by gamma spectrometry (via 236 keV peak from Th-227) or mass spectrometry.

3. Due to short Ac-225 half-life (10 days), drug must be used quickly.

4. Chelators (e.g., DOTA, macropa) must possess ultra-high affinity for actinides.

5. Special protection against alpha aerosols is required when working with Ac-225.

⚠️ Note: Ac-225 represents "gold standard" of future oncology but requires unprecedented level of quality control. Error of 0.01% in Ac-227 impurity can lead to serious long-term consequences for patient, so this utility uses strictest limits in industry.

input.csv

BatchNumber,RadiochemicalPurityPercent,FreeAc225Percent,DaughterNuclidesPercent,SpecificActivityGBq_per_mg,pH,EndotoxinsEU_per_mL,SterilityTest,ActivityMBq,RadionuclidicPurityPercent,Ac227ImpurityPercent
AC225-PSMA-2026-001,98.5,1.0,0.5,40.0,5.5,10.0,0,100.0,99.99,0.0005
AC225-DOTATATE-002,96.0,2.5,0.8,35.0,6.0,20.0,0,80.0,99.95,0.0008
AC225-Experimental-003,90.0,5.0,2.0,25.0,7.0,50.0,1,50.0,99.80,0.0020

URS & FS — user requirements and functional specification

URS — User Requirements Specification

The utility shall accept input.csv with these mandatory columns: BatchNumber, RadiochemicalPurityPercent, FreeAc225Percent, DaughterNuclidesPercent, SpecificActivityGBq_per_mg, pH, EndotoxinsEU_per_mL, SterilityTest, ActivityMBq, RadionuclidicPurityPercent, Ac227ImpurityPercent.
Each row shall be processed as a separate batch or record identified by BatchNumber.
Before evaluation, the utility shall validate the CSV structure, mandatory values, numeric fields and allowed text values.
Rules and limits shall be applied to every parameter in the input row.
Critical violations identified in the supplied description shall set the record result to FAIL.
Each row shall receive an overall PASS, WARNING or FAIL status with the triggered rules.
An invalid row shall not receive PASS.
output.json shall contain source values, applied limits, individual check results and errors.
The same input and the same rule profile shall produce the same result.

FS — Functional Specification

Run Ac225TargetedAlphaTherapyQC.exe in demonstration mode or with input.csv output.json arguments.
Read UTF-8 CSV and verify the exact set of mandatory columns.
Convert row values to numeric and text types.
Apply the rules defined in the approved version or configuration profile.
Generate individual check results and derive the overall status from the most severe violation.
Write machine-readable output.json.
Structural and type errors shall be reported explicitly and shall not be masked by a successful status.

Complete input.csv example

BatchNumber,RadiochemicalPurityPercent,FreeAc225Percent,DaughterNuclidesPercent,SpecificActivityGBq_per_mg,pH,EndotoxinsEU_per_mL,SterilityTest,ActivityMBq,RadionuclidicPurityPercent,Ac227ImpurityPercent
AC225-PSMA-2026-001,98.5,1.0,0.5,40.0,5.5,10.0,0,100.0,99.99,0.0005
AC225-DOTATATE-002,96.0,2.5,0.8,35.0,6.0,20.0,0,80.0,99.95,0.0008
AC225-Experimental-003,90.0,5.0,2.0,25.0,7.0,50.0,1,50.0,99.80,0.0020

Purpose of the supplied test rows

The first row contains values consistent with the criteria stated in the supplied description.
The second row contains values closer to the limits or moderate deviations.
The third row contains clear deviations for negative-result testing.

Minimum output.json structure

{
  "utility": "Ac225TargetedAlphaTherapyQC",
  "source": "input.csv",
  "results": [
    {
      "batchNumber": "BATCH-001",
      "status": "PASS",
      "checks": [
        {
          "parameter": "ParameterName",
          "value": 0,
          "limit": "configured rule",
          "status": "PASS"
        }
      ],
      "errors": []
    }
  ]
}

Minimum OQ scenarios

Process the complete supplied input.csv.
Remove a mandatory column and confirm a contract error.
Provide text instead of a numeric value and confirm a type error.
Test values directly on the configured limits.
Repeat the run with the same input and confirm an identical result.

Before operational use

Reconcile rules and limits with the approved specification, methods and SOP.
Fix the executable version and rule-profile version.
Retain the source CSV together with the generated JSON.

Included in packages

PetRad QC Suite

A specialised utility package for radiopharmaceutical quality control: PET, SPECT, therapeutic radionuclides, generators and decay calculations.

Ac225TargetedAlphaTherapyQC