SpecificActivityCalculator

Specific Activity Calculator

radiopharmaceuticals QC URS & FS input.csv output.json alpha therapy PET SPECT

Utility description: Specific Activity Calculator

Specific Activity Calculator — Radiopharmaceutical Specific Activity Calculation

ℹ️ Calculates specific activity (MBq/nmol) with decay correction.
ℹ️ Supports F-18, Ga-68, Lu-177, Ac-225, Y-90, Cu-64, etc.

Usage:
SpecificActivityCalculator.exe → demo mode
SpecificActivityCalculator.exe input.csv output.json → calculation

Input format:
BatchNumber,Radionuclide,Measured_Activity_MBq,Measurement_Time_ISO,Mass_Ligand_ug,Molecular_Weight_g_mol,Reference_Time_ISO,Min_Specific_Activity_MBq_nmol

Example:
LU177-SA-001,Lu-177,7400.0,2026-05-20T08:00:00,50.0,1435.6,2026-05-20T08:00:00,1000.0

— WHY IS THIS NEEDED?
Specific Activity (SA) is a key quality parameter for targeted therapy and diagnostics:
• Binding Efficiency: High SA ensures that most ligand molecules carry a radionuclide. Low SA means presence of "cold" ligand, which competes for receptors, reducing imaging or therapeutic efficacy.
• Toxicity: Excess cold ligand may cause pharmacological effects or toxicity.
• Quality Control: SA is calculated from measured activity (dose calibrator) and ligand amount (HPLC/spectrophotometry).
• Decay: Activity changes over time, so it is important to specify measurement time and reference time (e.g., injection time).

⚠️ IMPORTANT:
• Molecular weight must correspond to the ligand form (free peptide or metal complex).
• For generator isotopes (Ga-68, Re-188), SA is often limited by generator capacity and labeling efficiency.
• For alpha-emitters (Ac-225), SA requirements are extremely high due to high toxicity of free ions.

input.csv

BatchNumber,Radionuclide,Measured_Activity_MBq,Measurement_Time_ISO,Mass_Ligand_ug,Molecular_Weight_g_mol,Reference_Time_ISO,Min_Specific_Activity_MBq_nmol
LU177-SA-001,Lu-177,7400.0,2026-05-20T08:00:00,50.0,1435.6,2026-05-20T08:00:00,1000.0
AC225-SA-001,Ac-225,10.0,2026-05-20T08:00:00,5.0,1200.0,2026-05-20T08:00:00,5000.0

URS & FS — User Requirements and Functional Specification

1. Scope

This document defines requirements and functional behaviour for SpecificActivityCalculator used to control: Specific Activity Calculator. The utility is intended for QC use and applies deterministic rules, not machine learning.

2. Execution modes

SpecificActivityCalculator.exe — demo mode or help output.
SpecificActivityCalculator.exe input.csv output.json — process user data and write result.

3. Key source-derived controls

Specific Activity Calculator — Radiopharmaceutical Specific Activity Calculation
• Toxicity: Excess cold ligand may cause pharmacological effects or toxicity.
• Quality Control: SA is calculated from measured activity (dose calibrator) and ligand amount (HPLC/spectrophotometry).
⚠️ IMPORTANT:
• For alpha-emitters (Ac-225), SA requirements are extremely high due to high toxicity of free ions.

4. URS — user requirements

ID	Requirement	Criticality	Acceptance criterion
URS-001	The utility shall accept input.csv with the exact headers defined in the data contract.	High	The file is processed without manual header changes.
URS-002	The utility shall validate mandatory fields, data types, ranges, units, and critical pharmaceutical/radiochemical limits.	High	Each row receives PASS/WARNING/FAIL status.
URS-003	The utility shall detect critical deviations related to radionuclidic/radiochemical purity, impurities, free radionuclide, pH, endotoxins and sterility where such fields are present.	High	A critical deviation produces FAIL or an explicit critical finding.
URS-004	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-005	The utility shall not use machine learning to decide conformance.	Medium	The decision is based on explicit rules and thresholds.
URS-006	The utility shall preserve traceability between batch number, input values, applied rules and final status.	High	The output contains batch identifier and checked parameters.
URS-007	The documentation shall support IQ/OQ preparation and inspection discussion with FDA/EMA/Roszdravnadzor or local regulator.	Medium	URS/FS and test scenarios are supplied with the utility.

5. input.csv contract

#	Field	Type	Sample	Purpose
1	`BatchNumber`	string	`LU177-SA-001`	Batch or lot identifier.
2	`Radionuclide`	decimal	`Lu-177`	Controlled input parameter from input.csv.
3	`Measured_Activity_MBq`	decimal	`7400.0`	Activity of the radiopharmaceutical material or finished product.
4	`Measurement_Time_ISO`	decimal	`2026-05-20T08:00:00`	Controlled input parameter from input.csv.
5	`Mass_Ligand_ug`	decimal	`50.0`	Controlled input parameter from input.csv.
6	`Molecular_Weight_g_mol`	decimal	`1435.6`	Controlled input parameter from input.csv.
7	`Reference_Time_ISO`	decimal	`2026-05-20T08:00:00`	Controlled input parameter from input.csv.
8	`Min_Specific_Activity_MBq_nmol`	decimal	`1000.0`	Activity of the radiopharmaceutical material or finished product.

BatchNumber,Radionuclide,Measured_Activity_MBq,Measurement_Time_ISO,Mass_Ligand_ug,Molecular_Weight_g_mol,Reference_Time_ISO,Min_Specific_Activity_MBq_nmol
LU177-SA-001,Lu-177,7400.0,2026-05-20T08:00:00,50.0,1435.6,2026-05-20T08:00:00,1000.0
AC225-SA-001,Ac-225,10.0,2026-05-20T08:00:00,5.0,1200.0,2026-05-20T08:00:00,5000.0

6. FS — functional specification

ID	Function	Implementation
FS-001	CSV import	Read input.csv in UTF-8/CSV-compatible format; validate header and expected columns.
FS-002	Schema validation	Validate mandatory fields and column count; report unknown or missing key fields.
FS-003	Type conversion	Convert numeric, flag and text values; record invalid format as row-level error.
FS-004	Rule engine	Apply domain rules for Specific Activity Calculator, including critical limits from the utility description.
FS-005	Status aggregation	Generate final status: FAIL for critical failure, WARNING for non-critical deviation, PASS for conformance.
FS-006	JSON export	Write output.json with check details, source values, warnings and critical findings.
FS-007	Audit support	Keep result structure suitable for review, deviation investigation and IQ/OQ preparation.

7. output.json example

{
  "utilityId": "specific-activity-calculator",
  "api": "Specific Activity Calculator",
  "overallStatus": "PASS|WARNING|FAIL",
  "sourceFile": "input.csv",
  "checks": [
    {
      "parameter": "BatchNumber",
      "value": "LU177-SA-001",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Radionuclide",
      "value": "Lu-177",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Measured_Activity_MBq",
      "value": "7400.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Measurement_Time_ISO",
      "value": "2026-05-20T08:00:00",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Mass_Ligand_ug",
      "value": "50.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Molecular_Weight_g_mol",
      "value": "1435.6",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Reference_Time_ISO",
      "value": "2026-05-20T08:00:00",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Min_Specific_Activity_MBq_nmol",
      "value": "1000.0",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    }
  ],
  "criticalFindings": []
}

8. OQ/PQ test scenarios

ID	Scenario	Expected result
OQ-001	Valid sample row	PASS or acceptable WARNING according to rules.
OQ-002	Mandatory column is 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	Approved review result with input.csv and output.json retained.

9. QA/QC and change control

Do not rename columns without validator update.
Store 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 checked against the approved specification and local SOPs.

Included in packages

PetRad2: advanced radiopharmaceutical QC package

A curated set of new utilities for radionuclide control, targeted alpha therapy, specific activity, radiolysis stability and preliminary dosimetry calculations.

Open

Radiology QC Suite

QC package for radiology and diagnostic imaging: radiopharmaceuticals, PET/SPECT, contrast media, iodinated and gadolinium products, plus particle, sterility and endotoxin checks.

Open

RPH isotope family: alpha-emitting therapy

Ac-225, Ra-223, At-211, Bi-213 and Th-227: targeted alpha therapy and daughter/recoil control.

Open

RPH isotope family: beta-emitting therapy

Lu-177, Y-90, Ho-166, Re-188, Sm-153, Sr-89, P-32, Cu-67 and Tb-161.

Open

RPH isotope family: Ga/Ge

Ga-67, Ga-68 and Ge-68: generator, radiolabelling, PET/SPECT and purity workflows.

Open

RPH isotope family: long-lived PET / immuno-PET

Cu-64, Zr-89, I-124, Mn-52 and Y-86 for antibodies, slow kinetics and extended imaging.

Open

RPH organ/system: oncology and theranostics

Tumour imaging, PSMA/FAPI/receptor tracers, immuno-PET, targeted radionuclide therapy and radioembolization.

Open

RPH use case: radionuclide therapy and theranostics

Lu-177, Ac-225, Ra-223, Y-90, Ho-166, Sm-153, Sr-89, Re-188, Tb-161, I-131 and other therapeutic radiopharmaceuticals: activity, purity, free metal, daughters and toxicological constraints.

Open

RPH workflow: generators and isotope purity

Generator eluate, breakthrough, radionuclidic purity, isotope mix and starting radionuclides.

Open

RPH workflow: imaging QC and quantitative interpretation

Acquisition, uptake, clearance, perfusion, transit, ejection fraction, segmentation and quantitative imaging.

Open

RPH workflow: product release QC

Assay, purity, sterility, endotoxins, pH, impurities, appearance and batch-release checks.

Open

RPH workflow: stability, storage, decay and waste

Kinetic stability, shelf life, decay correction, expiry, storage, trend and radioactive waste.

Open

RPH workflow: synthesis, labelling and kit reconstitution

Radiolabelling, synthesis, chelation, reducing agent, pH/stoichiometry and kit preparation.

Open

RPH: combined radiopharmaceutical QC package

RPH combines PetRad, PetRad2 and PetRad3 into one umbrella package for PET/SPECT, therapeutic radionuclides, generators, labelled compounds, decay calculations, sterility, endotoxins and radiochemical/radionuclidic purity.

Open