A Novel Device for Deep-Inspiration Breath Hold (DIBH): Results from a Single-Institution Phase 2 Clinical Trial for Patients with Left-Sided Breast Cancer

Purpose: To validate a novel device developed at our institution for deep inspiration breath hold (DIBH) within a phase 2 clinical trial for left-sided breast cancer and to evaluate the dosimetric benefits of its use. Methods and Materials: The device uses an external mechanical reference for guiding the patient to the desired breath level and gives acoustic and visual feedback to the patient and the radiation therapists, respectively. A phase 2 clinical trial was performed for its validation. The thoracic amplitude was used as a surrogate of the inspiration level. The stability, repeatability, reproducibility, and reliability of DIBH using the device were analyzed. The dosimetric parameters of the heart, the left anterior descending coronary artery, the ipsilateral lung, the contralateral breast, and the target coverage using free breathing and DIBH were compared. Results: Thirty-eight patients were included in the analysis. The maximum population value of stability and repeatability were 1.7 mm and 3.3 mm, respectively. The reproducibility mean value was 1.7 mm, and population systematic and random errors were 0.3 mm and 0.9 mm, respectively. The reliability was 98.9%. Statistically significant dose reductions were found for the heart, the left anterior descending coronary artery, and the ipsilateral lung dosimetric parameters in DIBH, without losing dose coverage to the planning target volumes. Conclusions: The validation of the device within the phase 2 clinical trial demonstrates that it offers reliable, stable, repeatable, and reproducible breast cancer treatments in DIBH with its dosimetric benefits. (C) 2020 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.