Comparison of two close-packing methods for vertex placement in lattice radiotherapy (LRT)

Background

Lattice Radiation Therapy (LRT) is characterized by its 3D-mouldated spatial dose distribution of vertices inside the lattice volume with high peak-to-valley dose ratio (PVDR) for enhancing tumor control and reducing normal tissue toxicity. While face-centered cubic (FCC) and hexagonal close-packed (HCP), both achieving maximum spatial packing density, have been used for vertex placement, a direct comparative analysis of their dosimetric performance is lacking.