DaughterNuclideIngrowthCalculator

Daughter Nuclide Ingrowth Calculator

radiopharmaceuticals QC URS & FS input.csv output.json radiochemical purity radionuclidic purity calculation

Utility description: Daughter Nuclide Ingrowth Calculator

Daughter Nuclide Ingrowth Calculator — Calculator for Daughter Nuclide Accumulation

ℹ️  Utility calculates theoretical activity of daughter isotopes in radiopharmaceutical generators:
    • Supported pairs: Mo-99/Tc-99m, Sr-82/Rb-82, Ge-68/Ga-68, Ti-44/Sc-44, Zn-62/Cu-62
    • Calculation using Bateman equations
    • Determination of radioactive equilibrium type
    • Accounts for time elapsed since last elution or purification

⚠️  IMPORTANT: Calculation assumes daughter nuclide activity is zero at T0 (complete elution).
    Real elution yield may be lower due to column efficiency.

Usage:
  DaughterNuclideIngrowthCalculator.exe                            → demo mode
  DaughterNuclideIngrowthCalculator.exe input.csv output.json      → calculate your data

Input format:
BatchNumber,ParentIsotope,InitialParentActivityMBq,ElapsedTimeHours,DaughterHalfLifeHours,ParentHalfLifeHours

Example (0 in Half-Life fields uses built-in tabulated values):
  GEN-MO99-001,Mo-99,10000,24,0,0

Supported isotopes (automatic half-life selection):
• Mo-99 (65.94 h) → Tc-99m (6.01 h)
• Sr-82 (25.36 h) → Rb-82 (1.27 min)
• Ge-68 (271 days) → Ga-68 (67.7 min)
• Ti-44 (60 years) → Sc-44 (3.97 h)
• Zn-62 (9.19 h) → Cu-62 (9.7 min)

— WHY IS THIS NEEDED?
Generator systems are widely used in radiopharmacy, where a short-lived diagnostic or therapeutic isotope is obtained from a long-lived parent:
• Elution Planning: Calculating available activity before procedure
• Quality Control: Comparing theoretical yield with measured to assess generator efficiency
• Logistics: Estimating activity for delivery to remote centers

⚠️  CRITICAL:
• Equilibrium Type:
  - Secular (T_parent >> T_daughter): Daughter activity approaches parent activity.
  - Transient (T_parent > T_daughter): Daughter activity can exceed parent activity at a certain point.
• Time to Maximum: For transient equilibrium, there is an optimal accumulation time (t_max) when daughter activity is maximal.
• Elution Yield: Real Activity = Theoretical * Elution Efficiency (typically 80-95%).

Key features:
• Automatic decay constant calculation
• Support for custom half-lives for non-standard pairs
• Equilibrium type determination for correct result interpretation

💡 Usage tips:
1. For Mo-99/Tc-99m, maximum ingrowth is reached approximately 23 hours after previous elution.
2. For Ga-68 generators (Ge-68), equilibrium is reached quickly, but due to the long parent half-life, activity drops slowly (mainly due to Ge-68 decay in the long term, but nearly constant over days).
3. Always account for Elution Efficiency when planning patient doses.

input.csv

BatchNumber,ParentIsotope,InitialParentActivityMBq,ElapsedTimeHours,DaughterHalfLifeHours,ParentHalfLifeHours
GEN-MO99-001,Mo-99,10000,24,0,0
GEN-SR82-002,Sr-82,1850,0.5,0,0
GEN-GA68-003,Ge-68,500,48,0,0
CUSTOM-001,Parent-X,1000,10,2.5,20

URS & FS — User Requirements and Functional Specification

This document describes the controlled interface and behaviour of DaughterNuclideIngrowthCalculator for Daughter Nuclide Ingrowth Calculator.

Domain limits and critical parameters

Key fragments from the source description are shown below. Before production use, limits must be verified against the approved specification, registration dossier and local SOPs.

⚠️ IMPORTANT: Calculation assumes daughter nuclide activity is zero at T0 (complete elution).
⚠️ CRITICAL:

URS — User Requirements Specification

ID	Requirement	Criticality	Acceptance criterion
URS-001	The utility shall accept an `input.csv` file with the exact headers defined in the data contract.	High	The file is processed without manual header editing.
URS-002	The utility shall perform deterministic QC evaluation for Daughter Nuclide Ingrowth Calculator using input values, approved limits and domain rules.	High	Each input row receives a `PASS / WARNING / FAIL` status.
URS-003	The utility shall validate mandatory fields, data types, numeric ranges, units and pharmaceutical/radiochemical plausibility.	High	Schema and conversion errors are explicitly reported.
URS-004	The utility shall identify critical deviations related to radionuclidic purity, radiochemical purity, free radionuclide, impurities, pH, endotoxins and sterility when such fields are present.	High	A critical deviation causes FAIL or a separate critical finding.
URS-005	The utility shall generate `output.json` with machine-readable results, source values, warnings and failures.	High	JSON is suitable for LIMS/ELN/MES integration and QA/QC review.
URS-006	The utility shall not use machine learning to decide conformance.	Medium	The result is based on explicit rules, thresholds and input values.
URS-007	The utility shall preserve traceability between batch number, input values, applied rules and final status.	High	The output contains the batch identifier and the list of checked parameters.
URS-008	The documentation shall support IQ/OQ preparation and inspection discussion with FDA/EMA/Roszdravnadzor or local regulators.	Medium	URS & FS, `input.csv`/`output.json` contract and test scenarios are supplied with the utility.

input.csv contract

#	Field	Type	Sample	Purpose
1	`BatchNumber`	string	`GEN-MO99-001`	Batch or lot identifier used for traceability.
2	`ParentIsotope`	string / decimal	`Mo-99`	Controlled input parameter used by the deterministic QC rules.
3	`InitialParentActivityMBq`	decimal	`10000`	Radioactivity value used for release, decay or dose-related assessment.
4	`ElapsedTimeHours`	datetime / string	`24`	Time point used for decay, stability or ingrowth calculation.
5	`DaughterHalfLifeHours`	decimal	`0`	Controlled input parameter used by the deterministic QC rules.
6	`ParentHalfLifeHours`	decimal	`0`	Controlled input parameter used by the deterministic QC rules.

BatchNumber,ParentIsotope,InitialParentActivityMBq,ElapsedTimeHours,DaughterHalfLifeHours,ParentHalfLifeHours
GEN-MO99-001,Mo-99,10000,24,0,0
GEN-SR82-002,Sr-82,1850,0.5,0,0
GEN-GA68-003,Ge-68,500,48,0,0
CUSTOM-001,Parent-X,1000,10,2.5,20

FS — Functional Specification

ID	Function	Implementation
FS-001	CSV import	Read `input.csv` in UTF-8/CSV-compatible format and validate the header and expected columns.
FS-002	Schema validation	Check mandatory fields and column count; report unknown or missing key fields.
FS-003	Type conversion	Convert numeric, flag and text values; invalid formats are recorded as row-level errors.
FS-004	Domain rule engine	Apply domain rules for Daughter Nuclide Ingrowth Calculator, including critical limits from the utility description and approved specification.
FS-005	Status aggregation	Produce final status: FAIL for critical failure, WARNING for non-critical deviation, PASS for conformance.
FS-006	JSON export	Write `output.json` with detailed checks, source values, warnings, failures and critical findings.
FS-007	Audit support	Keep the result structure suitable for review, deviation investigation, calculation reproduction and IQ/OQ preparation.
FS-008	Integration contract	Support the production scenario: LIMS/ELN/MES creates `input.csv`, the utility returns `output.json`, the portal displays description and documentation.

Example output.json

{
  "utilityId": "daughter-nuclide-ingrowth-calculator",
  "api": "Daughter Nuclide Ingrowth Calculator",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "GEN-MO99-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "ParentIsotope",
      "value": "Mo-99",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "InitialParentActivityMBq",
      "value": "10000",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "ElapsedTimeHours",
      "value": "24",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "DaughterHalfLifeHours",
      "value": "0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "ParentHalfLifeHours",
      "value": "0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    }
  ],
  "criticalFindings": []
}

OQ/PQ test scenarios

ID	Scenario	Expected result
OQ-001	Valid sample row	PASS or acceptable WARNING according to the rules.
OQ-002	Mandatory column missing	Schema error or FAIL.
OQ-003	Non-numeric value in numeric field	Type-conversion error.
OQ-004	Critical parameter outside limit	FAIL and critical finding.
PQ-001	User real batch/lot	Reviewed result with `input.csv` and `output.json` retained.

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.

Included in packages

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