AAPM Task Group Application Series
A report-grounded dosimetry application for executing reference calibration work, documenting evidence, preserving session history, and exposing a constrained assistant that can explain protocol logic without replacing it.
Preview data
Grounding stack
TG-51 protocol with 2014, 2022, and 2024 direct guidance and addenda
TG-21 available for rationale and protocol comparison
TG-351 reserved for migration planning, not for overriding TG-51 execution
Live Workbench Signals
Math Reference
Apply all chamber and atmospheric corrections before converting charge to absorbed dose.
Reference absorbed dose to water for photon beams under TG-51 conditions.
Electron reference dosimetry adds the gradient correction when the setup requires it.
Sample Calculation Table
| Factor | Symbol | Value | Role |
|---|---|---|---|
| Ion recombination | Pion | 1.0029 | Two-voltage recombination correction for pulsed beams. |
| Polarity | Ppol | 0.9986 | Correction for polarity dependence. |
| Temperature-pressure | PTP | 1.0000 | Normalizes the reading to reference atmosphere. |
| Electrometer | Pelec | 1.0004 | Calibration traceability for the readout chain. |
| Beam quality | kQ | 0.9920 | Maps the reference coefficient to the clinical beam quality. |
Recent Session Table
| Session | Beam | Date | Dose | Delta | Status |
|---|---|---|---|---|---|
| TG51-20260427-0003 | 6X | Apr 27, 2026 | 1.0162 Gy | +1.62% | action required |
| TG51-20260425-0002 | 6X | Apr 25, 2026 | 1.0005 Gy | +0.05% | completed |
| TG51-20260424-0001 | 10X | Apr 24, 2026 | 0.9982 Gy | -0.18% | completed |
Operating rules
Percent Difference Trend
The line chart shows recent dose-to-reference deltas by session.
Status Breakdown
Use this bar view to spot unresolved calibration work at a glance.
OpenTOPAS Monte Carlo
Plan or execute a TG-51 water-tank Monte Carlo study with a Farmer-type ion chamber at reference depth, then keep the primary dosimetry deck plus a bundled Qt/OpenGL visualization companion tied to this workbench.
Physics Preview
Preview simulation ready
Clinically motivated 6 MV template bremsstrahlung spectrum with 1.2 mm focal-spot sigma and 3.5 mrad angular spread.
Depth-dose preview is physics-informed planning data for the current deck, not a substitute for completed Monte Carlo scoring.
80.0 × 80.0 × 240.0 cm
16.0 × 16.0 × 18.0 cm
6.0 × 6.0 × 18.0 cm
40.0 × 40.0 × 40.0 cm
0.2 × 0.2 × 30.0 cm
0.7 × 0.7 × 2.6 cm
0.6 × 0.6 × 2.3 cm
Launch the local Qt/OpenGL companion from this workbench to inspect the simplified TrueBeam head, water tank, and Farmer chamber. This path is interactive only, uses the TG-51 backend host's configured OpenTOPAS binary, and is not physics-valid until the staged geometry is overlap-free.
This Monte Carlo plan is attached to the TG-51 session evidence record.
Primary session worksheet signed by the performing physicist.
Engine: OpenTOPAS Status: planned Beam: TrueBeam-A 6X (6 MV) Source model: linac_spectrum Beam source: Clinically motivated 6 MV template bremsstrahlung spectrum with 1.2 mm focal-spot sigma and 3.5 mrad angular spread. Clinical setup: water tank with a Farmer-type ionization chamber centered at 10.0 cm. Qt visualization companion: bundled local launcher and OpenGL deck stage a simplified treatment head, water tank, and chamber for qualitative inspection.
# OpenTOPAS TG-51 Monte Carlo setup: topas-preview-6x # This deck models a beam-in-water reference dosimetry configuration with a clinical reference chamber for TG-51 style studies. # Qt/OpenGL visualization companion artifacts are bundled separately for local qualitative inspection. # Source model: linac_spectrum # Source summary: Clinically motivated 6 MV template bremsstrahlung spectrum with 1.2 mm focal-spot sigma and 3.5 mrad angular spread. s:Ge/World/Type = "TsBox" d:Ge/World/HLX = 40.00 cm d:Ge/World/HLY = 40.00 cm d:Ge/World/HLZ = 120.00 cm s:Ge/Phantom/Type = "TsBox" s:Ge/Phantom/Material = "G4_WATER" # Clinical setup: water tank with a Farmer-type ionization chamber centered at reference depth. s:Ge/ReferenceChamberWall/Parent = "Phantom" s:Ge/ReferenceChamberWall/Type = "TsCylinder" d:Ge/ReferenceChamberWall/RMax = 0.35 cm d:Ge/ReferenceChamberWall/HL = 1.30 cm d:Ge/ReferenceChamberWall/RotY = 90. deg d:Ge/ReferenceChamberWall/TransZ = -10.00 cm s:Ge/ReferenceChamberWall/Material = "G4_GRAPHITE" s:Ge/ReferenceChamberCavity/Parent = "ReferenceChamberWall" s:Ge/ReferenceChamberCavity/Type = "TsCylinder" d:Ge/ReferenceChamberCavity/RMax = 0.305 cm d:Ge/ReferenceChamberCavity/HL = 1.15 cm s:Ge/ReferenceChamberCavity/Material = "G4_AIR" s:So/Beam/Type = "Beam" s:So/Beam/BeamEnergySpectrumType = "Continuous" s:Sc/DepthDose/Quantity = "DoseToWater" # Uncomment locally for interactive Qt/OpenGL visualization. # s:Gr/View/Type = "OpenGL" # s:Gr/View/ColorBy = "Material"
Recent Monte Carlo plans
Session Drill-down
Open a calibration session to inspect measurements, findings, linked simulations, and downloadable evidence without leaving the workbench.
Reference TG-51 output session with linked Monte Carlo planning evidence.
| Observation | Dose | Delta | Status |
|---|---|---|---|
| reference | 1.0002 Gy | +0.02% | within tolerance |
major · open · opened Apr 27, 2026, 12:05 PM
Repeat measurement and verify output calibration before releasing the session.
Evidence And Downloads
Primary session worksheet signed by the performing physicist.
Engine: OpenTOPAS Status: planned Beam: TrueBeam-A 6X (6 MV) Source model: linac_spectrum Beam source: Clinically motivated 6 MV template bremsstrahlung spectrum with 1.2 mm focal-spot sigma and 3.5 mrad angular spread. Clinical setup: water tank with a Farmer-type ionization chamber centered at 10.0 cm. Qt visualization companion: bundled local launcher and OpenGL deck stage a simplified treatment head, water tank, and chamber for qualitative inspection.
Linked simulations
Clinically motivated 6 MV template bremsstrahlung spectrum with 1.2 mm focal-spot sigma and 3.5 mrad angular spread.
TG-51 Assistant
This assistant retrieves TG-51 chunks first and only expands into lineage context when you ask for it.
Grounded Answer
Ready
Scope: TG-51 primary sources only. Grounded summary: [1] AAPM's TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams, Unlabeled section, pages 1-2: The protocol defines clinical reference dosimetry for high-energy photon and electron beams using an absorbed-dose-to-water formalism. Use the cited report text as authority; do not treat this answer as a substitute for protocol review.
The protocol defines clinical reference dosimetry for high-energy photon and electron beams using an absorbed-dose-to-water formalism.