Multileaf collimator with alternating trapezoidal leaf geometry design

A multi-level multileaf collimator (MLC), comprising a first MLC in a first level distal to a source and a second MLC in a second level proximal to the source, wherein the second MLC comprises:

• a plurality of beam-blocking leaves of a first type, each of the beam-blocking leaves of the first type having a trapezoidal geometry viewed in a longitudinal moving direction with a first lateral side, a second lateral side, a wider end and a narrower end, the wider end being proximal to a source;
• a plurality of beam-blocking leaves of a second type, each of the beam-blocking leaves of the second type having a trapezoidal geometry viewed in the longitudinal moving direction with a first lateral side, a second lateral side, a wider end and a narrower end, the wider base being distal to the source;
• and
• the beam-blocking leaves of the first type being alternatingly arranged with the beam-blocking leaves of the second type side by side.

An apparatus, comprising:

• a source of radiation, and
• a multileaf collimator comprising:
• a plurality of beam-blocking leaves of a first type, each of the beam-blocking leaves of the first type having a trapezoidal geometry viewed in a longitudinal moving direction with a first lateral side, a second lateral side, a wider end and a narrower end, the wider end being proximal to a source;
• a plurality of beam-blocking leaves of a second type, each of the beam-blocking leaves of the second type having a trapezoidal geometry viewed in the longitudinal moving direction with a first lateral side, a second lateral side, a wider end and a narrower end, the wider end being distal to the source;
• and
• the beam-blocking leaves of the first type being alternatingly arranged with the beam-blocking leaves of the second type side by side