The Plaque Loading Window

The Plaque window is used to select a plaque, load sources into a plaque, and design new plaques. In this example the plaque file EP1824-25-n-p-f-r.iplq6 has been loaded. Plaque file naming conventions are fully explained in the plaque name page of this guide. For example, the "p" in the file name indicates that this plaque model includes an embedded scanned photo of the plaque. The extension ".iplq6" indicates that this is a PS version 6 plaque file. PS version 6 plaques are packages (a package is a folder masquerading as a file) which contains an xml file describing the plaque and .png files with pictures of the shell and seed carrier if there is one. PS version 5 files were binary files. PS version 6 can import and convert most version 5 binary files.

The status line just below the tool bar indicates the active plaque index (P1..P4) and information concerning the current radionuclide inventory selection.

To load sources into a plaque, select a batch of sources from the radionuclide inventory database by clicking on the Source button. The status line will change to reflect the active inventory selection. Set the cursor mode to Load slot, and then click on a slot position placeholder. Slot placeholders typically appear as thin brown lines. Filled positions are drawn with a 3D rendering of the source. To return a source to the inventory, simply click on it. As you add sources to the plaque they will also appear in any other windows which display sources.

In addition to the buttons in this window, many other plaque related parameters and functions are accessible from the Plaque menu which appears on the menu bar any time this window is frontmost.

Plaque window

Toolbar controls

The toolbar buttons near the top of the window select which plaque is currently being edited, cursor function, and window layout. Plaque simulator supports up to 4 plaques per plan. The default condition is to allow only one of these plaques to be "active", or "editable", for dosimetry purposes. In most instances you will simply use plaque #1 for planning, with plaques 2..4 reserved to optionally compare alternate plaque designs and loading patterns.


Plaque 1..4 - Selects the plaque that is currently "active" and editable.

Load slot
Sets the cursor mode for loading and unloading sources into the slot placeholders.
Drag and rotate
Sets the cursor mode for dragging and rotating source slots.
Drag slot label
Sets the cursor mode for dragging a slot's label position.
Edit slot
Sets the cursor mode for editing a slot's parameters.
Cut slot
Sets the cursor mode for deleting slots from the plaque.
Select slot
Sets the cursor mode for selecting a set of sources or placeholders (slots) in the plaque for future action such as loading or unloading. Selected sources and placeholders are tinted blue to indicate membership in the set of selected slots. Clicking on a source or placeholder toggles its membership in the selection set. You can click and drag a rectangular selection marquee around a group of sources or placeholders to simultaneously select multiple slots. Clicking away from a slot deselects all slots. The number of currently selected slots is listed in the status line just below the toolbar.
Paste source
Sets the cursor mode for pasting source loading from the clipboard into a single slot.
Sets the cursor mode for opening and displaying additional slot loading parameters in the Source Inspector window.

Single pane
Sets the window layout to display only the "active" plaque as determined by the plaque button.
Four pane
Divides the window layout into 4 panes to display all four plaques. The pane of the active plaque is bounded with a thicker black frame.

Rental Plaques - Convenience access to the IsoAid rental plaques menu.

Duplicate 1..4 - Select a plaque (other than the active plaque) to duplicate. The currently active plaque (e.g. plaque #1) will become a duplicate of the selected plaque (e.g. #2, #3 or #4). The plaque model, name, shell structure, ocular location, angular orientation, source loading and so on are all duplicated. During the duplication process, an alert dialog will offer the option to also duplicate and substitute new inventory database entries for sources in the duplicate. This allows you to later revise (e.g. intensity modulate) sources in the duplicate without affecting the calibration of sources in the original plaque. This convenience function is available in PS version 6.6.2 and greater.

Left side controls

The buttons on the left of the Plaque window (from top to bottom) control various aspects of the plaque and its display in this window:

  • Rulers - Superimposes a ruled grid on the plaque to assist with plaque design. The rulers can be dragged by clicking on them.
  • Labels - Labels each source with its strength at time of implant and other optional information.
  • RotationMenuCarrier rotation - if a plaque has a carrier (such as the COMS and ROPES plaques) this control rotates the carrier around the central axis of the plaque. The corner arrows within this control rotate the carrier clockwise or counter clockwise in 1 or 90 deg. increments. You can also drag the indicator. This control also offers options to rotate the entire plaque and embedded pictures of the face or carrier. To access these contextual options control-click (or right mouse button) the control and select the desired control context.
  • Source - Opens the radionuclide inventory window.
  • Picture - enables display of a scanned picture of the plaque if one is available.
  • Load - Loads the set of selected placeholders, or all placeholders if none are selected, with the currently selected inventory entry.
  • Unload - Returns selected sources, or all sources if none are selected, to the inventory entry from which they originated.
  • Face (view) - Switches between face (concave) and back (convex) views of the plaque.
  • Lock - Locks the radionuclide in a plaque. A password is required to unlock and edit the radionuclide of a locked plaque. Locking the plaque loading is primarily used to protect permanently loaded plaques files such as the BEBIG Ru-106 plaques.
  • Auto Dose - When enabled, planar and retinal dose matrices are automatically recalculated after any change to the plaque loading or location or the dosimetry surface. Enabling auto dose is not recommended for Ru plaques due to the much longer calculation time required.
  • Normalize - Click to normalize the sources and their inventory entries such that the lowest strength source in the plaque will be 1.0 units (e.g. mCi) on the implant date. This is a convenience function which simplifies manual intensity modulation. For example, in the example above 3 seeds surrounding the optic disc notch are intensity modulated at 2X the strength of the other sources. To try another ratio, such as 1.5X, normalize the plaque and then change the strength of the inventory for the 3 seeds to 1.5 and solve for source strengths in the Implant Calculator.
  • Contrib. - This is a convenience service. The same functionality can be achieved and further refined in the label options menu. When enabled, each loaded source is labeled with its dosimetric contribution to points of interest including the Rx point, fovea, disc and a selected user defined point. The contribution of each source is expressed as a percentage of the overall dose rate at the point of interest. This information is usefull when considering intensity modulation of a few sources in order to assure margin coverage or to spare a critical site. Sometimes the seed physically closest to a point of interest might not actually contribute to dose at that point due to collimation.

    Note: contributions can not be calculated for empty source placeholders, you must first load seeds into the plaque. For example, to assure dosimetric coverage of a peripapilary tumor overlying the disc, initially load a notched plaque with seeds of uniform strength and take note of which seeds contribute the largest percentage of dose to the disc. Intensity modulate only those seeds.

Footer controls

Opens the Window Size Dialog dialog.

Zoom out
Reduces the plaque size by a factor of 2.
Zoom in
Enlarges the plaque image by a factor of 2.
Resets the plaque image size to its standard settings.
Opens the Plaque Appearance window wherein you can change the appearance of rendered elements.
Enables automatic scaling of source labels as a function of window frame size and zoom magnification.
Slider manually adjusts the font size used for source labels (this slider becomes active when the auto scaling checkbox is disabled).

Edit menu

When the Plaque window is frontmost, the Edit menu provides access to a few special functions.


If NO sources are selected, copies the current source loading data for all sources to the clipboard. You can later paste these sources into a different plaque.


If ANY sources are selected, copies the current source loading data for those currently selected sources to the clipboard. You can later paste these sources into a different plaque.


Pastes previously copied source loading data into the current plaque.


Option-click the Edit menu to access the special copy function which transfers the center coordinates of all of a plaque's sources and placeholders to the clipboard in X,Y,Z tab delimited text format. You can then paste the coordinates into a spreadsheet or text editor.