A seven-year experience of using moderate deep inspiration breath-hold for patients with early-stage breast cancer and dosimetric comparison

We present our seven-year experience of using moderate deep inspiration breath-hold (mDIBH) with an active breathing control (ABC) device for patients with early-stage breast cancer and dosimetric comparison to evaluate the benefit of mDIBH on the heart, lung, and liver. We retrospectively reviewed all patients with newly diagnosed breast cancer and having clinical stage Tis, I, or II disease treated between November 2010 and October 2017. Among the 369 patients included in this study, 107 patients were treated with mDIBH and 262 patients were treated with free breathing (FB). Dosimetric analysis was performed to compare dose distribution in the heart, lung, and liver between the two treatment groups. The chi-square test was used to compare the distribution of stage and tumor site between the two groups. The independent samples t-test was used to compare the remaining parameters between the two groups. For all 369 patients, there was a significantly lower ipsilateral lung V(5) (relative volume receiving ≧5 Gy), ipsilateral lung V(10), ipsilateral lung V(20), mean ipsilateral lung dose, whole lung V(5), whole lung V(10), whole lung V(20), mean whole lung dose, heart V(10), heart V(30), heart V(40), and mean heart dose in the mDIBH group. For 184 patients with a left-sided breast tumor, significantly lower ipsilateral lung V(5), ipsilateral lung V(10), ipsilateral lung V(20), mean ipsilateral lung dose, whole lung V(10), whole lung V(20), mean whole lung dose, heart V(10), heart V(30), heart V(40), and mean heart dose were observed in the mDIBH group. For 185 patients with a right-sided breast tumor, significantly lower ipsilateral lung V(5), ipsilateral lung V(10), ipsilateral lung V(20), mean ipsilateral lung dose, whole lung V(5), whole lung V(10), whole lung V(20), mean whole lung dose, heart V(10), heart V(30), heart V(40), mean heart dose, liver V(30), and mean liver dose were observed in the mDIBH group. For early-stage breast cancer patients, mDIBH reduces not only the heart dose but also the lung and liver doses. The routine integration of mDIBH using an ABC device may decrease radiation-induced toxicity in the heart, lung, and liver.