Evaluation of beam-on time and number of breath-holds using a flattening-filter-free beam with the deep inspiration breath-hold method in left-sided breast cancer.

We performed a dosimetric study to evaluate the benefits of using a flattening-filter-free (FFF) beam with the deep inspiration breath-hold (DIBH) method for left-breast cancer. We used data from 30 previous patients with treatment plans that included DIBH for left-breast cancer with a flattened beam. FFF beam plans were calculated from previous treatment plan images and compared to the original plans in terms of monitor units (MU), number of segments, beam-on time, and breath-holds.