Calibrating the BEBIG CGD Plaque

In this tutorial we will create a model of plaque CGD282 from the sample data sheets.

Prepare the eye model
  • BEBIG plaques should be calibrated using an eye model that matches the curvature of the plaque.
  • The curvature of the CGD plaque is designed to fit a 26 mm diameter sphere.
  • At startup, the default PS eye model model is a 24 mm spherical eye.
  • If the current eye model is not a 26 mm diameter spherical eye, from the Setup window click the Size button SizeButton42x42 to open the Eye Size window and set the eye size to a 26 mm diameter sphere by clicking the D=26 mm button.

Step 1
  • Bring the Plaque window to the front.
  • Select plaque #1.
  • The displayed plaque will most likely be whatever your preferred startup plaque is. Whatever plaque is displayed, ignore it! We are going to replace it in the next step.

Step 2
  • From the Plaque menu at the top of the screen, select the BEBIG Plaques item and then the desired model (CGD in this case) from the menu of plaques.

An empty CGD plaque will appear in the Plaque window.


Step 3
  • Click the Central Axis Measurements tab if it is not already selected.

Step 4
  • In the BEBIG Calibration window, click the Show Profiles button located near the lower right corner of the window.ShowProfilesCorner
  • This will open the Documents preview window, position the window adjacent to the BEBIG Calibration window, and select the Profile document page.

Step 5
  • Enter the Serial no. CGD 282.
  • Enter the Plaque file name CGD_282tutorial (the .iplq6 extension will be added automatically when the file is saved).
  • Enter the Measured activity 27.2 from the Measurements certificate sheet.
  • Enter the Assay date 9/19/2011 12:00 PM.
  • Select Radionuclide ID 106M from the popup menu (the dialog should default to 106M).
  • Select Central axis protocol 11 point (0.6...10.0) from the popup menu (the dialog should default to this).
  • Enter the central axis data from the Measurements protocol sheet.

Step 6
  • Click the Distribute Activity Uniformly button.DistributeUniformlyCorner
  • The uncalibrated dose profile should appear as illustrated.

Step 7
  • Click the Optimize Nearfield button.OptimizeNearfieldGroup
  • A progress dialog will appear.

Step 8

When the nearfield optimization is complete the dialog and dose profile will look like this: