Physics Bucharest 2017

Beam Modifiers Approximations

 A line can be drawn from a sub- source through the MLC to the isocenter plane  In the MLC this line is split up into many short intervals. For each end point of an interval it is determined whether the point falls inside or outside tungsten  One simply sums the geometric path lengths X 1 and X 2 in the leaf material to apply an attenuation correction

X 1

X 2

  yx e ,  