Radiation Planning Assistant – A Web-based Tool to Support High-quality Radiotherapy in Clinics with Limited Resources

All patient data used for evaluating the RPA were used retrospectively, with approval from The University of Texas MD Anderson Institutional Review Board. The RPA comprises a series of dashboards located to the left of the main menu of the RPA webpage (Figure 2). Figure 2 shows the main dashboard. All dashboards have a similar look but focus on different tasks and personnel. The following protocol describes the key processes for the automatic creation of a treatment plan.

Figure 2: Screenshot of the RPA main dashboard. Please click here to view a larger version of this figure.

1. Complete Service Request

1. To create and accept a new Service Request for automatic planning:
   1. Go to the Service Request dashboard by clicking on the Service Request channel.
   2. Click on New Form to generate a new Service Request form.
   3. In Section 1: Demographics, complete the questions. Select the treatment technique from the Treatment pulldown. Click on the individual in the treatment technique pulldown to access further details of the treatment technique.
   4. In Section 2: Treatment-General Questions, complete the questions. These questions are the same for all patients; their purpose is to actively engage the user in determining whether the RPA Plan is appropriate for the current patient.
   5. Section 3: Treatment-Specific Questions, complete the questions for the selected treatment approach, including details of the treatment targets and prescription.
   6. Click on submit. Once the Service Request PDF has been automatically generated, select the patient in the patient list (on the Service Request dashboard). Review the Service Request PDF (Figure 3), scrolling if necessary, and click on Accept to approve the Service Request.
      NOTE: This PDF must be accepted by a radiation oncologist before the RPA will initiate automated contouring and planning. The status of the RPA Plan can be determined on the Service Request page, as shown in Table 2. An example Service Request that was created for a soft tissue-based 4-field plan for cervical cancer is shown in Figure 3.

Table 2: Patient status categories for the Service Request Dashboard.

Figure 3: An example Service Request created for a soft tissue-based 4-field plan for cervical cancer. Please click here to view a larger version of this figure.

2. Upload CT scan and accept for automated planning

Figure 4 shows a screenshot of the CT review workspace. To upload and review a CT scan:

Figure 4: A screenshot of the CT review workspace. Please click here to view a larger version of this figure.

1. Go to the CT Scans dashboard by clicking on the CT Scans channel.
2. Click the Upload CT button. Select the folder where the CT scan (DICOM format) is stored using the folder explorer that automatically opens. Follow the prompts to confirm the selection.
3. Review the uploaded CT scan by selecting the patient in the patient list to open the CT viewer for this patient (Figure 4), and then use the following controls:
   1. Load the entire 3D CT image set by clicking on Load CT.
      NOTE: Other navigation tools are not active until this is complete.
   2. Scroll between slices in all views, and use any of the following tools:
      1. Click on <, > buttons below each CT view to move to the next slice.
      2. Click on <<, >> buttons below each CT view to move five slices in the selected direction.
      3. Mouse scroll wheel: Move the cursor over any CT view and then use the mouse scroll wheel to scroll between slices.
      4. Click the Intersect button to overlay a crosshair on each CT view (axial, coronal, and sagittal). Click on any of the three views to move the crosshair to this point-the other views will follow accordingly. Click the Intersect button to turn this tool on/off.
      5. Click the Zoom/Pan button. Further review the image using the mouse wheel to zoom the view where the cursor is positioned or right-click and hold down on a CT view and then move the mouse to pan.
      6. Click on Marked Iso to move the CT views to the marked isocenter (based on automated detection of three radiopaque markers).
         NOTE: This button is inactive if the 3D CT image set has not been loaded (click Load 3D to resolve this) or if the RPA was unable to detect a marked isocenter (as identified with a three-point setup).
4. Click on the Ref Point button to add a reference point.
   1. Move the three views to the desired Reference Point location using the intersect tool.
   2. Click on the Ref Point button to add a Reference Point.
   3. If a Reference Point has already been selected, clicking on Ref Point will move the three views to this point.
      NOTE: This button adds a Reference Point to an image if a Reference Point does not exist. It can also move the CT image views to the Reference Point if one already exists. A new Reference Point can only be selected for CT scans that have not been accepted. Below are the steps to add a Reference Point:
   4. To select a new Reference Point, first clear the current Reference Point by clicking on Clear Ref Point and then add a new one. The RPA only Accepts one Reference Point.
5. Accept the CT scan. After reviewing the patient's CT scan as already described above, perform the following steps:
   1. Answer the questions below the CT images to minimize risk and reduce the occurrence of errors in the subsequent RPA calculations.
   2. Select Accept and follow the prompts.
      ​NOTE: This task can be performed by anybody identified as a Clinical User of the RPA. The status categories of current patients can be viewed on the CT Scans dashboard and are shown in Table 3.

Table 3: Patient status categories for the CT Scans dashboard.

3. Monitor planning progress

The status categories of current patients can be viewed on the main dashboard (Table 4). To perform a preliminary review of any completed RPA plan and download it for use:

Table 4: Patient status categories for the main dashboard.

1. Review a completed RPA plan by selecting the patient and then selecting Review at the top of the main dashboard. Review the RPA Plan Report (PDF) for that patient that automatically opens in a new tab.
   NOTE: The RPA Plan Report PDF can also be accessed from the download window.
2. Download a completed RPA Plan by clicking on the download icon. Wait for a window to open and the DICOM files, along with the RPA Plan Report (PDF), will be downloaded for import into the treatment planning system.

4. Importing the RPA Plan into the User's treatment planning system and reviewing for clinical use

NOTE: Once the RPA plan is downloaded (DICOM files), the following steps should be completed in the user's treatment planning system:

1. Import the patient's CT scan into the local TPS. This is the original scan that was uploaded to the RPA.
2. Import the RPA Plan and RPA contours into the local TPS.
3. Recalculate the dose using the local commissioned dose calculation algorithm and the used fixed MU option.
4. Compare the imported contours and calculated dose with those in the RPA Report (to check for correct import).
5. Review the plan for appropriateness and edit as necessary.
   ​NOTE: This step may include editing field shapes and renormalizing the fields. It is very important that the clinical team review the final plan in their treatment planning system and make any edits before clinical use.

5. Uploading the Final Plan to the RPA website and reviewing the automatic comparison of the Final Plan and the RPA Plan

Patients for whom an RPA Plan has been generated will appear in the plan comparison dashboard. The plan comparison dashboard provides the status categories shown in Table 5 for current patients. To upload the final User Plan and review an automatic comparison of the User Plan and the RPA Plan:

Table 5: Patient status categories for the plan comparison dashboard.

1. Select the patient and then click on Upload Plan.
2. Select the DICOM structure file, plan, and dose files for upload.
3. Review the Plan Comparison Report by first selecting the patient. Then, review the Plan Comparison report (Figure 5) which opens at the bottom of the screen, (an example is shown in Figure 5).

Figure 5: An example of the automatic plan comparison report. Please click here to view a larger version of this figure.