VARIAN REAL-TIME POSITION MANAGEMENT SYSTEM OVERVIEW VERIFICATION OF MARKER BLOCK POSITION AFTER TREATMENT COUCH SHIFTS

Correct patient breathing baseline selection, using Varian Real-time Position Management (RPM) system, is the first important step for correct patient positioning and gating during a radiation therapy session. In this work, possible blind spots in the acquisition of the respiratory baseline are discussed. Using an optical surface monitoring system AlignRT to verify actual RPM position, highlights the potential for an unseen shift in patient position and breathing pattern, and prompts a discussion and recommendations on how to minimize it.