MatBED_B&C: A 3-dimensional biologically effective dose analytic approach for the retrospective study of gamma knife radiosurgery in a B&C model

The biological effect of irradiation is not solely determined by the physical dose. Gamma knife radiosurgery may be influenced by dose rate, beam-on-time, numbers of iso-centers, the gap between the individual iso-centers, and the dose‒response of various tissues. The biologically effective dose (BED) for radiosurgery considers these issues. Millions of patients treated with Models B and C provide a vast database to mine BED-related information. This research aims to develop MatBED_B&C, a 3-dimensional (3D) BED analytic approach, to generate a BED for individual voxels in the calculation matrix with related parameters extracted from Gammaplan. This approach calculates the distribution profiles of the BED in radiosurgical targets and organs at risk. A BED calculated on a voxel-by-voxel basis can be used to show the 3D morphology of the iso-BED surface and visualize the BED spatial distribution in the target. A 200 × 200 × 200 matrix can cover a greater range of the organ at risk. The BED calculated by MatBED_B&C can also be used to form BED-volume histograms to generate plan quality metrics, which will be studied in a retrospective study of gamma knife radiosurgery to guide future BED planning. • We develop MatBED_B&C to calculate the 3D BED in radiosurgical targets. • The BED of MatBED_B&C can visualize the BED spatial distribution profiles. • The BED of MatBED_B&C will generate plan quality metrics studied in a retrospective study.