The Study of Field Equivalence Determined by the Modeled Percentage Depth Dose in Electron Beam Radiation Therapy

Table 2

The best fitting of the PDD modeled by the main parameters , , and in 5 electron energies at a cone size of .

Electron energy (MeV)
	3.1	90	0.001
	6.2	210	0.0007
	8.9	290	0.0005
	12.3	400	0.0003
	15.1	470	0.0002

Note: is a scalar of harden factor, is a scalar of the spread factor while is the linear attenuation factor in the unit of mm^-1. The is a real number on the horizontal axis in the unit of mm, also denotes the depth in water.