Simulated patient realignment compensates for a portion of the CTV to PTV margin (the size, shape and position of the RSCV) while still leaving some uncertainty (e.g., patient respiration, daily setup). Therefore it is hypothesized that we can decrease the PTV needed with simulated realignment. We will consider a decrease in the PTV margin by ≥ 3 mm with simulated patient realignment justification for progression to Stage II of this study.