Patient Coaching for Deep Inspiration Breath Hold Decreases Set-up Duration and Left Anterior Descending Artery Dose for Left-sided Breast Cancer Radiotherapy

Purpose: To show the impact of patient coaching and home practice using the deep inspiration breath hold (DIBH) technique on radiation treatment set-up times and cardiac at-risk doses. Methods: The study involved patients who received tangential field radiotherapy using the DIBH technique for treating left breast cancer. Patients were divided into two groups: the first group consisted of those who received coaching from an oncology nurse and were given an instruction sheet at least 1 week before the computed tomography (CT) simulation. The second group consisted of those who were only taught how to hold their breath by the radiation technician on the simulation day and without further education. During treatment, the patients were monitored using the Varian RPM™respiratory gating system, and 2D kV orthogonal imaging was performed daily. The setup duration of each patient was noted and compared between treatment groups. For each patient, the dose-volume histograms (DVHs) of the heart, LAD (left anterior descending artery), were calculated and compared for both coached DIBH (cDIBH) and non-coached DIBH (ncDIBH). Results: Thirty-six coached and 28 non-coached patients were identified. Compared with ncDIBH, coached patients were older (55.5 versus 46.5, p=0.003) and had a significantly higher BMI (body mass index) (29.95 versus 26.32 kg/m2, p=0.006). Nevertheless, in more than half of the treatment fractions, the set-up duration was detected to be statistically longer in the ncDIBH group than in the cDIBH group. Additionally, the LAD max dose was significantly lower in the cDIBH group (36.5 versus 29.5, P=0.02). Conclusion: Coaching at least 1 week before the simulation with an instruction sheet decreased the simulation time, and the cardiac LAD max dose should be further decreased by this method.