Purpose: The feasibility to use visually guided voluntary breath-hold with and without audio assistance to reduce the total treatment time was evaluated.
Materials and methods: Patients referred for gated SBRT received hypofractionation schedules for lung or liver treatments. The patients were treated with the Novalis system (BrainLAB AG, Feldkirchen, Germany) and IGRT was performed with ExacTrac5.0/NovalisBody allowing gated irradiation. Video glasses, used for visual feedback to guide voluntary breath-hold, allowed additional audio assistance during treatment. The technique was applied for 25 patients of whom 9 were treated in free breathing, 7 had only visual feedback and another 9 had both audio and visual feedback.
Results: The delivery time of gated treatment during free breathing had an average value of 1.7 min/100 MU (SD 0.6 min/100 MU). The introduction of visual feedback reduced the average delivery time to 1.4 min/100 MU (SD 0.4 min/100 MU). The treatments with additional audio assistance indicated a significant reduction (p=0.004) of the average delivery time to 0.9 min/100 MU (SD 0.2 min/100 MU).
Conclusion: The introduction of visually guided voluntary breath-hold with audio assistance led to treatment times for gated radiation therapy approaching conformal beam delivery times, which made gated treatments applicable in conventional treatment time slots.