A Beam-Specific Optimization Target Volume for Stereotactic Proton Pencil Beam Scanning Therapy for Locally Advanced Pancreatic Cancer.

ABSTRACT:

Purpose

We investigate two margin-based schemes for optimization target volumes (OTV), both isotropic expansion (2 mm) and beam-specific OTV, to account for uncertainties due to the setup errors and range uncertainties in pancreatic stereotactic pencil beam scanning (PBS) proton therapy. Also, as 2-mm being one of the extreme sizes of margin, we also study whether the plan quality of 2-mm uniform expansion could be comparable to other plan schemes.

Methods and materials

We developed 2 schemes for OTV: (1) a uniform expansion of 2 mm (OTV_2mm) for setup uncertainty and (2) a water equivalent thickness-based, beam-specific expansion (OTV_WET) on beam direction and 2 mm expansion laterally. Six LAPC patients were planned with a prescribed dose of 33 Gy (RBE)

SUBMITTER: Han D 

PROVIDER: S-EPMC8463829 | biostudies-literature | 2021 Nov-Dec

REPOSITORIES: biostudies-literature