Shoulder Block

Rather than blocking using a structure, the goal with blocking in RayStation (version 8 SPb) is to place a point near the top of each shoulder. The script then determines where the lower (Y1) jaw needs to be placed on sub-arcs to avoid treating through the shoulder.

1. Go to the Plan Design>Module Specific Scripts>UW Plan Setup

2. Select Add Shoulder Blocking VMAT Beams

3. Complete the dialog as follows:

   a. Rx Target: Highest Dose PTV

   b. Beamset Name: As per procedure (note the Beamset name must be unique)

   c. Number of Fractions and Dose From TPO for highest dose target

   d. Treatment Machine: StX or TrueBeam

   e. Technique: VMAT

   f. Target for Isocenter:

   • All_PTVs is a good choice if all targets are to be treated by this beamset

   • Otherwise, the most central and largest of the PTV’s

   g. Beamset to load: 2 Arc VMAT – HN Shoulder Block

4. Place the Points Block_L_Inf_POI and Block_R_Inf_POI as follows (see Figure 1):

   a. Set a lung window to maximize the low HU of the skin

   b. In the Coronal View (lateral placement):

   • Scroll to the acromial clavicular joint and place the crosshair

   c. In the Axial view (vertical placement):

   • Scroll up until the top of the shoulder is present, and place crosshair. d. In the Sagittal view (anterior placement):
   • No scrolling. Place the point at the superior-most portion of the shoulder e. After points are placed, continue the script execution

5. When point placement is complete, confirm the placement is correct. Figure 2

6. Confirm the Beam Optimization Settings are changed to limit the lateral arcs to use jaw limits.

7. Proceed with the Automated Plan Optimization script.