SU‐FF‐T‐13: A Fast Scan‐Plan‐Treat Mode for Topographic Breast Treatment Delivery

Purpose: To develop a fast scan‐plan‐treat mode that can deliver breast treatments within 15 minutes Method and Materials: With the advent of on‐line CT imaging capability, it becomes increasingly feasible to use a radiation therapy system as a single‐source device to image, plan, and deliver a patient treatment, in as little as 10–20 minutes from patient entry to exit. Such a mode can be particularly useful for cord compressions and emergency treatments. This concept is here expanded to deliver breast treatments using topotherapy, or a radiation therapy treatment delivered with concurrent couch motion but with a fixed gantry angle. MLC modulation may accompany this motion. The goal of this work was to explore: Whether auto‐contouring could be used to define breast and sensitive structures. Whether this process could be completed in 10‐20 minutes. The adequacy of the plans given the time constraints on both optimization and delivery Results: It was determined that auto‐contouring could successfully contour the ipsilateral breast, the contralateral breast, each lung, and the trachea in less than 1 minute. Planning could be completed in less than 5 minutes through use of an optimization template, along with less than 5 minutes for imaging, and less than 5 minutes for delivery of 2 topographic angles. The plan optimized in this manner treated the target breast with a homogeneity of +/− 5%, and sensitive structure sparing equivalent to a conventional breast plan. Subsequent fractions can be currently created with this tool, or treated with alternate off‐line optimizations. Conclusion: The scan‐plan‐treat paradigm can be combined with a topotherapy‐style delivery to enable breast treatments in less than 20 minutes from the time a patient first enters the clinic. This work was supported by TomoTherapy Inc.