Bilateral breast treatment in a single arc using RapidArc Dynamic: A planning comparison with conventional volumetric modulated arc therapy

PURPOSE: Synchronous bilateral breast cancer (SBBC) presents significant radiotherapy planning challenges due to complex target volumes near critical organs. This study evaluated RapidArc Dynamic (RAD), a novel technique integrating dynamic arcs with static angle modulated ports (STAMPs) via simultaneous GPU-accelerated optimization, against conventional volumetric modulated arc therapy (VMAT) for SBBC treatment planning and delivery efficiency. METHODS: ). Planning time, monitor units (MU), and measured delivery times were also assessed. RESULTS: by 5.4 Gy (p = 0.002). RAD significantly reduced planning time (avg 16 vs. 39 min), mean MU (1654 vs. 2268; ∼30% reduction), and mean measured delivery time (2.2 vs. 5.8 min; ∼62% reduction). CONCLUSION: For SBBC radiotherapy, RAD demonstrated significant dosimetric improvements over conventional VMAT, particularly reducing low-dose lung and high-dose esophageal irradiation while enhancing target homogeneity. The substantial gains in planning and delivery efficiency further establish RAD as a highly advantageous technique for managing these complex cases.