Lateral Penumbra Modelling Based Leaf End Shape Optimization for Multileaf Collimator in Radiotherapy

Table 3

Leaf end curve constraints.

Type	Bound constraints	Linear constraints
Circular arc
	Elliptical arc
Bézier curve		,		,
	B-spline	,	,
, ,

Leaf end is straight when tends to infinity.
The special case of elliptical arc is circular arc when equals .