Select a TG-51 Reference Data Set

A reference data set lets Quadrant obtain beam-quality and clinical percent depth dose (PDD) values from existing scan data. It is optional because you can enter custom depth-dose or R₅₀ values in the calibration wizard.

For electrons, Quadrant records beam-quality PDD evidence separately from clinical-normalization PDD evidence. One scan can supply both only when its energy, mode, field, and geometry satisfy both roles. See Understand TG-51 Protocols and Saved Evidence.

Understand PDD and TMR

Percent depth dose (PDD) and tissue-maximum ratio (TMR) are clinical depth-dose quantities. PDD is used for an SSD setup, while TMR is used for an SAD setup. Use the quantity that matches the machine’s clinical setup and verified scan data.

Select Reference Data

1. Open Calibration > TG-51 > Reference Data Set.
2. Confirm the TG-51 data set shown in the header.
3. Select the reference institution.
4. Select the reference linear accelerator.
5. Select the reference data set.
6. Review the pending change.
7. Click Save.

What Quadrant Uses

When you add a photon or electron calibration, the PDD Values step can analyze matching depth-dose data for the selected energy and mode.

Result	What to Do
Matching reference data is available	Review the displayed reference values before continuing.
No matching energy or mode is available	Choose Enter Custom Values and enter values from the verified source.
Reference analysis fails	Confirm the selected data set and scan availability, then use verified custom values if appropriate.

Electron scan analysis is PDD-only. Quadrant does not perform PDI-to-PDD conversion or detector-position correction during this workflow. Complete any required conversion or correction before import.

For the scan-derived TG-51 summary, see Databook.

Clear or Change the Reference

Click Clear Selection when the TG-51 record should not use scan-based reference values.

Caution

Changing or clearing the reference can affect saved photon and electron calibrations. Review every affected energy in the shared recalculation workflow. Resolve all blocking problems or click Cancel to leave the reference change unsaved. Save All Recalculations preserves previous versions and does not skip or retire energies whose reference data is unavailable.

Confirm the Result

Open a photon or electron calibration wizard and check that Use Reference Data Set shows the intended source and values. Cancel the wizard if you are only confirming the reference.

Continue with Add a Photon TG-51 Calibration. For an electron-only data set, continue with Add an Electron TG-51 Calibration.