A NOVEL DEVICE FOR DEEP-INSPIRATION BREATH HOLD (DIBH): RESULTS FROM A SINGLE INSTITUTION PHASE II CLINICAL TRIAL FOR LEFT-SIDED BREAST CANCER PATIENTS

Abstract Purpose To validate a novel device developed at our institution for deep-inspiration breath hold (DIBH) within a phase II clinical trial for left-sided breast cancer and to evaluate the dosimetric benefits of its use. Materials and Methods 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 (RTT), respectively. A phase II 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 the DIBH using the device were analyzed. The dosimetric parameters of the heart, the left anterior descending coronary artery (LAD), the ipsilateral lung, the contralateral breast and the target coverage in free breathing and in 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 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 LAD and the ipsilateral lung dosimetric parameters in DIBH, without losing dose coverage to the PTVs. Conclusion The validation of the device within the phase II clinical trial demonstrates that it offers reliable, stable, repeatable, and reproducible breast cancer treatments in DIBH with its dosimetric benefits.