Intrapulmonary percussive ventilation to achieve prolonged breath-hold for radiation treatments

Introduction: Thoracic or abdominal tumours present a breathing-related motion that can reduce accuracy of radiation treatments. Therefore, motion mitigation strategies have been developed to ensure adequate target dose coverage during successive radiotherapy fractions. In this trial, we investigated a technique that intends to prolong breath-hold while coupling it with Intrapulmonary Percussive Ventilation (IPV), performed with a non-invasive IPV device (Pegaso A-Cough Perc). Our aim was to determine a standardized training protocol allowing a prolonged breath-hold combined to IPV (BHPV), with a maximal reduction of thoracic movement. Methods: Ten volunteers underwent a training protocol divided in three training sessions in order to get used to IPV and to attempt to achieve a BHPV of 10 min. Afterwards, the volunteers performed a final BHPV for a least 10 min (max. 20 min) in the radiotherapy simulation room. During this final BHPV, residual thoracic motion was measured from a tracked point, using an optical tracking system. Stabilization time and stable phase duration were also recorded. Results: All the 10 subjects achieved BHPV of 10 min. During the final BHPV, all the subjects even reached the maximal duration allowed of 20 min. Seven out of ten subjects presented a motion deviation of only 1mm around the mean position for more than 95% of the duration of the stable phase. The mean stabilization time was 2.1 ± 3.3 min and the mean stable phase duration was 16.6 ± 5.5 min. Conclusion: This training protocol allowed a 20min-BHPV. It is based on the combination of breath-hold with IPV while using a commercially available device.