Purpose: Tumor motion during respiration presents a challenge in delivering high-precision stereotactic ablative radiation therapy (SABR) for lung cancer. While inspiratory breath-hold techniques can minimize motion, they are often limited by the patients' ability to sustain prolonged breath-holds and the variability that comes with repeat breath-holds. We present the first-in-human demonstration of the feasibility and safety of percussive ventilation breath-hold (PVB) to eliminate the uncertainty of breath-hold reproducibility between confirmatory volumetric image guidance and delivery of lung tumor SABR by completing both within the same assisted breath-hold. Here, we report that 4 patients were successfully treated as initial observations from a prospective clinical trial of PVB-SABR.

Methods and materials: Four patients with lung tumors were treated in a prospective, institutional review board-approved study in which they underwent an education and evaluation session to assess their tolerance for PVB, followed by treatment with PVB-SABR.

Results: All 4 patients successfully completed PVB-SABR. The mean PVB duration per fraction from the beginning of the final cone beam computed tomography image verification to the end of SABR delivery was 6 minutes 56 seconds in a single PVB. Within that time, the mean delivery time per fraction was 2 minutes 22 seconds and the mean duty cycle was 93.5%.

Conclusions: These initial observations in a first prospective trial of PVB-SABR demonstrate the feasibility of PVB to enable completion of SABR delivery within the same effective breath-hold as confirmatory volumetric imaging, eliminating the uncertainty of interbreath-hold reproducibility.