SBRT Plan and Delivery Optimization for Central Lung Tumors on the Versa HD Using Elekta One Planning
Abstract
Purpose
This study aimed to assess three different planning approaches for treating central lung SBRT tumors using GPU Acceleration for optimization and GPUMCD for dose calculation in the Elekta One Planning treatment planning system (v6.2.3, EOP).
Methods
Three 6FFF VMAT plans were created for 5 different patients with prescriptions of 60 Gy in 8 fractions following the SUNSET protocol. Three planning approaches were investigated that specified the distribution of control points across an arc, including the use of two partial arcs with an arc increment combination of 20˚/10 ˚, two partial arcs with an arc increment combination of 30˚/15 ˚, and one partial arc with two passes with a 10˚arc increment. All plans were optimized similarly in terms of conformity, arc lengths, high fluence smoothing, limited to 150 max number of segments, normal target and avoidance margins, a 0.2 cm beamlet width, and calculated with a 2 mm dose grid.
Results
Clinically acceptable plans were generated for all optimization geometries and similar plan quality was seen for all plans. The estimated delivery time in seconds was found to be 231.2 ± 58.1, 244.77± 59.23, and 195.96 ± 54.80 for the 2 partial arcs with 20˚/10 ˚ arc, 30˚/15 ˚ arc increment, and the one partial arc with two passes, respectively.
Conclusion
The one partial arc with two passes was found to have the fastest delivery among the planning techniques investigated while maintaining consistent plan quality metrics. As a result, this planning approach seems advisable to use clinically since it best balances plan quality with treatment efficiency.