A robust VMAT delivery solution for single-fraction lung SABR utilizing FFF beams minimizing dosimetric compromise.

A robust VMAT delivery solution for single-fraction lung SABR utilizing FFF beams minimizing dosimetric compromise. J Appl Clin Med Phys. 2020 May 29;: Authors: Burton A, Offer K, Hardcastle N Abstract Peripheral lung lesions treated with a single fraction of stereotactic ablative body radiotherapy (SABR) utilizing volumetric modulated arc therapy (VMAT) delivery and flattening filter-free (FFF) beams represent a potentially high-risk scenario for clinically significant dose blurring effects due to interplay between the respiratory motion of the lesion and dynamic multi-leaf collimators (MLCs). The aim of this study was to determine an efficient means of developing low-modulation VMAT plans in the Eclipse treatment planning system (v15.5, Varian Medical Systems, Palo Alto, USA) in order to minimize this risk, while maintaining dosimetric quality. The study involved 19 patients where an internal target volume (ITV) was contoured to encompass the entire range of tumor motion, and a planning target volume (PTV) created using a 5-mm isotropic expansion of this contour. Each patient had seven plan variations created, with each rescaled to achieve the clinical planning goal for PTV coverage. All plan variations used the same field arrangement, and consisted of one dynamic conformal arc therapy (DCAT) plan, and six VMAT plans with varying degrees of modulation restriction, achieved through utilizing different combinations of the aperture sh...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research