The retinal diagram maps the 3D retinal surface onto a 2D polar diagram centered at the posterior pole of the eye. Digitized photographs of the retina can be applied to the diagram and to the 3D model to help locate the tumor base. Tumor height determined from ultrasound studies is used to model the tumor three dimensionally as a peak or dome.

• Upper Control Group: The buttons in this group are used to select the "active" tumor and control diagram appearance.
  • The four Tumor buttons select the active tumor. Plaque simulator supports up to four tumor masses per plan, but normally only one is "active" at any time.
  • The Peak and Dome buttons control the geometric shape of the tumor.
• Center Control Group:
  • Apex - This button opens the apex height dialog in which you enter the tumor height.
  • Std. - This button opens the Standard Tumor dialog in which you create a simple elliptical tumor by specifying its size and location.
  • Lock - Locks the tumor position.
  • Tumor - Begins manual drawing of the tumor base.
  • Clear - Deletes the "active" tumor.
  • Tablet - Enables tumor digitization from a graphics tablet.
  • LandMk - Begins manual drawing of anatomic landmarks. Control-click on this button to select the landmark color. The default color is red.
  • Clear (LandMk) - Deletes all "selected" landmarks.
  • Photo - Superimposes the diagram on a digitized and calibrated fundus photo.
• Lower Control Group:
  • Eye - Choose left or right eye.
  • Ruler - This button adds a distance measuring tool to the diagram. The ruler measures the chord or arc length between any two points on the diagram. The ruler is primarily used to measure tumor size and dosimetric margins around the tumor base. To use the ruler, simply drag the handle at each end to the desired position, or drag the distance indicator at the ruler center.
  • Labels - This button adds labels and tic marks at 1mm intervals to the polar diagram elements.
  • Matrix - enables isodose display. Control-click on this button to set the dose matrix size.
  • Lines - enables isodose lines & labels. Control-click on this button to set labeling options.
  • Tint - enables isodose tinting. Control-click on this button to set the tint intensity.