TG43ParameterChecker

TG43 Parameter

activity brachytherapy dosimetry radiopharma source calibration TG-43

TG-43 Parameter Checker — Brachytherapy Parameter Validation (AAPM TG-43U1)

ℹ️ The utility checks physical consistency of key TG-43 formalism parameters: dose rate constant (Λ), radial dose function g(r), and anisotropy function F(r,θ).
ℹ️ Identifies input errors, impossible physical values, and deviations from typical ranges for Ir-192, I-125, Pd-103.
ℹ️ Processing: only the FIRST record in input.csv file.
⚠️ Critical for safety! Errors in parameter tables lead to systematic dose calculation errors in entire Treatment Planning System (TPS).

Usage:
TG43ParameterChecker.exe → demo mode
TG43ParameterChecker.exe input.csv output.json → check data (first record only)

Input format:
SourceModel,Radionuclide,AirKermaStrength,DoseRateConstant,GeometryFactor,RadialDoseFunction,AnisotropyFunction,RadiusCm,AngleDeg

Example (Ir-192, point 1 cm, 90 deg):
mHDR-v2,Ir192,35000.0,1.108,0.985000,0.9950,0.9800,1.0,90.0

— WHY IS THIS NEEDED?
When importing new sources into TPS, physicist uploads parameter tables.
• Human factor: typos in decimal points or swapped columns possible.
• Physical inconsistency: g(r) cannot be negative, F(r,θ) cannot be > 1.2.
• Dose rate constant (Λ) is strictly defined for each nuclide type.
• Automated check filters gross errors before clinical use.
⚠️ CRITICAL:
• Λ for Ir-192: ~1.108 ± 5%. Values outside 1.0–1.2 suspicious.
• g(r): Always > 0. Sharp jumps indicate interpolation error.
• F(r,θ): Range [0, 1], close to 1 at equator (90°). Values > 1.1 require check.
• Geometry factor G(r,θ): Always > 0.
Critical parameters:
• Dose Rate Constant: Strict range depending on nuclide
• Radial Dose Function: > 0
• Anisotropy Function: [0, 1.2]
⚠️ Note: Utility uses heuristic rules based on AAPM TG-43U1 publications and updates (Rivard et al.). On anomalies detects FAIL/WARNING status. Result includes status and bilingual recommendation (RU/EN).

input.csv

SourceModel,Radionuclide,AirKermaStrength,DoseRateConstant,GeometryFactor,RadialDoseFunction,AnisotropyFunction,RadiusCm,AngleDeg
mHDR-v2,Ir192,35000.0,1.108,0.985000,0.9950,0.9800,1.0,90.0

URS & FS — user requirements and functional specification

This document defines user requirements and functional specification for the quality-control utility. It supports deployment discussion, IQ/OQ preparation and QC workflow integration.

Utility: TG43ParameterCheckerAPI / object: TG43 ParameterCategory: Radiation physics

1. Scope

The TG43 Parameter Checker utility is used for TG43 Parameter. The actual input.csv is the source of truth for the input structure; control criteria are defined by the executable and the domain description.

The utility does not use machine learning; decisions are produced by deterministic rules.

Categories: Radiation physics

Tags: activity, brachytherapy, dosimetry, radiopharma, source calibration, TG-43

2. Execution modes

TG43ParameterChecker.exe                            → demo mode
TG43ParameterChecker.exe input.csv output.json      → check data (first record only)

3. Key controlled areas

pH and physicochemical parameters
activity, decay and radiochemical purity

4. Domain limits and critical parameters

⚠️ Critical for safety! Errors in parameter tables lead to systematic dose calculation errors in entire Treatment Planning System (TPS).
Physical inconsistency: g(r) cannot be negative, F(r,θ) cannot be > 1.2.
⚠️ CRITICAL:
Λ for Ir-192: ~1.108 ± 5%. Values outside 1.0–1.2 suspicious.
g(r): Always > 0. Sharp jumps indicate interpolation error.
F(r,θ): Range [0, 1], close to 1 at equator (90°). Values > 1.1 require check.
Geometry factor G(r,θ): Always > 0.
Critical parameters:
Dose Rate Constant: Strict range depending on nuclide
Radial Dose Function: > 0
Anisotropy Function: [0, 1.2]
⚠️ Note: Utility uses heuristic rules based on AAPM TG-43U1 publications and updates (Rivard et al.). On anomalies detects FAIL/WARNING status. Result includes status and bilingual recommendation (RU/EN).

Limits stated in the description must be verified against the current approved specification, pharmacopoeial monograph and registration dossier before production use.

5. URS — user requirements

ID	Requirement	Criticality	Acceptance criterion
URS-001	The system shall accept an `input.csv` file for TG43 Parameter with the exact columns listed in the “Input data contract” section.	High	A file with the correct header is processed without manual editing; missing mandatory columns produce FAIL/import error.
URS-002	The system shall support execution without arguments in demo mode and execution with `input.csv output.json` for user data.	Medium	Both execution scenarios produce a predictable result or clear diagnostic error.
URS-003	The system shall perform rule-based controls for: pH and physicochemical parameters, activity, decay and radiochemical purity.	High	Each controlled parameter receives a status and message; the result does not depend on hidden Excel formulas or ML.
URS-004	The system shall preserve traceability between batch/lot, source values, applied rules and final verdict.	High	Output includes batch identifier, source values, parameter statuses and critical findings.
URS-005	The system shall generate machine-readable `output.json` for LIMS/ELN/MES, batch record and QA/QC review.	High	JSON contains overall status, check array, warnings, failures and source-file reference.
URS-006	The system shall support use in the client validation package: URS/FS, IQ/OQ preparation, installation and operational scenario checks.	High	The document, test scenarios and reproducible CSV/JSON flow are suitable for audit and internal approval.
URS-007	The system shall clearly separate technical data errors from specification nonconformities.	Medium	Schema/type errors are not mixed with pharmacopoeial deviations and are reported separately.

6. input.csv data contract

The source of truth for the input schema is the actual input.csv header. Column names are technical identifiers and are not translated.

#	Column	Type	Unit	Description	Sample	Control rule
1	`SourceModel`	text	as specified	Source Model	`mHDR-v2`	mandatory value; format and acceptability are checked by the utility
2	`Radionuclide`	text	as specified	Radionuclide	`Ir192`	mandatory value; format and acceptability are checked by the utility
3	`AirKermaStrength`	decimal	as specified	Air Kerma Strength	`35000.0`	mandatory numeric value; rule comparison is performed by the utility
4	`DoseRateConstant`	decimal	as specified	Dose Rate Constant	`1.108`	mandatory numeric value; rule comparison is performed by the utility
5	`GeometryFactor`	decimal	as specified	Geometry Factor	`0.985000`	mandatory numeric value; rule comparison is performed by the utility
6	`RadialDoseFunction`	decimal	as specified	Radial Dose Function	`0.9950`	mandatory numeric value; rule comparison is performed by the utility
7	`AnisotropyFunction`	decimal	as specified	Anisotropy Function	`0.9800`	mandatory numeric value; rule comparison is performed by the utility
8	`RadiusCm`	decimal	as specified	Radius Cm	`1.0`	mandatory numeric value; rule comparison is performed by the utility
9	`AngleDeg`	decimal	as specified	Angle Deg	`90.0`	mandatory numeric value; rule comparison is performed by the utility

CSV example

SourceModel,Radionuclide,AirKermaStrength,DoseRateConstant,GeometryFactor,RadialDoseFunction,AnisotropyFunction,RadiusCm,AngleDeg
mHDR-v2,Ir192,35000.0,1.108,0.985000,0.9950,0.9800,1.0,90.0

7. FS — functional specification

ID	Function	Implementation description
FS-001	CLI entry point	The executable `TG43ParameterChecker.exe` supports demo mode and `input.csv output.json` processing mode.
FS-002	CSV parser	The import module reads CSV, validates header, column presence/order, value count and encoding. Decimal values are expected with a dot separator.
FS-003	Field conversion	Each column is converted to the expected type: identifier, text, decimal number, date/time or boolean flag.
FS-004	Domain rule engine	For TG43 Parameter, explicit rules are applied: range, minimum, maximum, absence of prohibited flag, data completeness or calculation-based check.
FS-005	Criticality handling	Critical violations produce FAIL; non-critical deviations and incomplete data produce WARNING; full conformance produces PASS.
FS-006	JSON writer	`output.json` stores overall status, per-parameter results, source values, warnings, failures and diagnostic messages.
FS-007	Integration contract	The CSV → JSON format is stable for invocation from LIMS/ELN/MES, scheduled task or wrapper service.
FS-008	Error handling	Schema error, missing file, non-numeric value or JSON write failure returns diagnosable error without silent PASS.

8. output.json contract

The output file must be suitable for automated processing, audit review and correlation with the source input.csv row.

{
  "utility": "TG43ParameterChecker",
  "api": "TG43 Parameter",
  "batchNumber": "",
  "overallStatus": "PASS|WARNING|FAIL",
  "checkedAtUtc": "2026-05-18T00:00:00Z",
  "checks": [
    {
      "parameter": "SourceModel",
      "value": "mHDR-v2",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "Radionuclide",
      "value": "Ir192",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "AirKermaStrength",
      "value": "35000.0",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "DoseRateConstant",
      "value": "1.108",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "GeometryFactor",
      "value": "0.985000",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadialDoseFunction",
      "value": "0.9950",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "AnisotropyFunction",
      "value": "0.9800",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    },
    {
      "parameter": "RadiusCm",
      "value": "1.0",
      "unit": "as specified",
      "status": "PASS|WARNING|FAIL",
      "message": "Rule-based check result"
    }
  ],
  "criticalFindings": [],
  "sourceFile": "input.csv"
}

9. OQ/PQ test scenarios

ID	Scenario	Expected result
TC-001	Valid CSV with expected header and sample row	All rows are processed; output contains PASS/WARNING/FAIL and parameter-level detail.
TC-002	A mandatory input.csv column is missing	Import is rejected or the row receives FAIL with schema reference.
TC-003	A numeric field contains text or a blank value	Type conversion error is recorded; the result is not hidden as PASS.
TC-004	A parameter is outside specification or critical limit	Critical parameters produce FAIL; non-critical deviations produce WARNING according to the rule.
TC-008	Incorrect activity, reference time or radiochemical purity	FAIL/WARNING is produced with calculation traceability.

10. QA/QC, CSV and change control

Before production use, the client records executable version, checksum, specification/monograph version, test CSV, expected JSON and IQ/OQ results.
Column names must not be changed without updating the validator and test scenarios.
The source CSV, output.json and utility version should be stored together as an evidence package.
Any change in control rules must go through change control and repeated OQ scenario verification.

Included in packages

Radiation Physics QC Suite

Utilities for activity, dosimetry, brachytherapy sources, small-field corrections and TG-43 parameters.

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: radioiodine

I-123, I-124, I-125 and I-131 for diagnostics, therapy, labelling and purity control.

Open

RPH use case: PET scanner state, gamma camera and radiation physics

The linked medical-device/radiation-physics layer: PET detector QC, normalization, AC map, cross-calibration, TOF, gamma-camera uniformity, source strength and staff dose.

Open

RPH workflow: dosimetry and therapy planning

Activity planning, absorbed dose, organ dose, lung shunt, preplanning and therapy verification.

Open

RPH workflow: instruments, devices and radiation safety

PET/gamma-camera state, calibration, detector QC, energy window, TOF, shielding and radiation safety.

Open