“…As previously reported, additional measures could improve treatment duration times, notably applying a certain tolerance to minimal shifts required for online CBCT-guided patient positioning, usage of flattening filter-free beams to reduce beam delivery times and optimization of CBCT image reconstruction. 15,19,20 However, given the reported target stability, we plan to eliminate the mid-treatment CBCT acquisition in a stepwise manner, therefore significantly reducing the length of the procedure time by approximately 30%. According to margin analysis, the 5 mm PTV typically used was sufficient to cover the reported mid-treatment intrafraction displacements.…”