Introduction

This manual gives specific details on the radiation therapy treatment planning program RtDosePlan. The program is invoked by running the execution file RtDosePlan. A separate license is needed to run RtDosePlan.

This program uses the System 2100 library, a General Purpose Radiological Display System. Functions are added here to support treatment planning. For image display, contouring, solid model views, and image fusion, the System 2100 manual must be referred to.

At present, this program only supports planning with x-rays.

Warnings

Do not apply any results of the use of the program to a patient without independently verifying that the dose delivered to the patient is correct. This is required by the state of the art in radiation therapy and by the license agreement for this program.

Do not use this treatment planning program until the beam data and program has been reviewed for correctness.

The American Association of Physicist in Medicine Radiation Therapy Committee Task Group 53 has made recommendations on the quality control of treatment planning systems. See “Quality Assurance for Clinical Radiotherapy Treatment Planning” in Medical Physics, 25(10), October 1998, pages 1773-1829.

The implementation of a plan requires quality control procedures that the parameters of the plan are correctly performed on the treatment machine, and that the treatment fields are properly placed on the patient. Care must be given that the correct energy is selected.

Field shaping devices must be reviewed for correctness, both in the shape and their correct application to the patient.

Our product, Dosimetry Check, is recommended for the testing and review of plans before they are applied to a patient. The program will compute the dose to the patient using the measured fluence for each of the treatment fields. The absolute dose and dose distribution can be verified.

User Interface Summary

The user interface in the program consists of a toolbar across the top of the screen. Selecting items from the pull down menus or hitting pushbuttons on the toolbar will generally result in either pushing a new toolbar (on top of the screen in place of the prior toolbar) or in a popup dialog box. When a toolbar is pushed, there is a return button on the left side that is used to return to the prior toolbar. Popups are closed with a Dismiss, OK, or Close button, or other action as the particular case may be.

Down the right hand side of the screen is control for the display of images and creation of screens. Each screen consist of one or more frames. Within a frame an image may be displayed. The user can create screens and determine the number of frames in a screen. Each screen can be assigned a name and the user can select which screen to view. A contrast button is provided for the current frame. The current frame border is outlined in red. Clicking the mouse of a frame will select it to be the current frame. There is a button in the upper right hand corner of each frame to zoom that frame to full screen and back again. Middle mouse will generally zoom an image within a frame, right mouse will unzoom. For 3d room views, the field of view is changed with the middle and right mouse buttons. Below the Contrast button is a Rotate button for finer control of 3d room views.

Most toolbars and popups will have a Help button that will display information specific to the particular toolbar or popup to assist in the use of the program. This information is generally also available in the manuals. Reading the help screens will provide information on how to use the program.

Selecting a stacked image set will result in a screen being created to display all the images in the set. Options are available to reformat images on a different screen or to redisplay the entire image set on another screen. A stacked image set is a set of images that can define a three dimensional model of the patient. They are usually CT or MRI scans taken sequentially.

Planning Summary

To accomplish a treatment plan, these broad steps must be performed:

Read in a CT scan set that will be used to model the patient. CT scans must be used as the primary image set. The primary image set defines the body outline and the CT number to density conversion (however, a body outline could be copied from a fused image set like any other outlined volume).
You should use the auto-body outlining feature under the Contouring toolbar to create a skin contour that will define what is inside the patient and what is outside. Objects outside the skin contour are ignored for computational purposes. The skin contour is otherwise treated the same as other outlined regions of interest. You can otherwise select which outlined region to use as the skin boundary under the Options toolbar under the Stacked Image Set pull down.
You must specify a CT number to density conversion. Under the Stacked Image Set pull down go to the Options toolbar and select the Density toolbar.
You may outline regions of interest under the Contouring toolbar.
On the top main toolbar, under Applications, you select RtDosePlan to get the Plans toolbar. Note that dose volume histograms are under the Plans toolbar as you may want to compare different plans for the same outlined structure.
Under the Plans toolbar you may create a new plan, which will push the Plan toolbar. For a new plan you will have to first select the stacked image set which is to be the primary image set. Each plan will consist of the beams that you create for that plan. Each plan is assigned a unique name.
Under the Plan toolbar you can select which frames to display the plan in. This will not happen automatically as you may want to display different plans in different frames on the same screen.
Under the Plan toolbar you can create treatment beams. Each beam is assigned a unique name for that plan.
Under the Beam toolbar you can move and edit the beams.
Return to the Plan toolbar to select to compute the dose, under the Evaluate pull down.
Under the Plan toolbar you can specify the dose prescription and print a physics summary.
Hardcopy of isodose lines is made by using the print screen function (click the mouse on an image, hit the Print Screen button on the keyboard). The output print out is scaled. Only Post Script printers are supported.

The rest of this manual and the System 2100 manual should be referred to for more details.