Abstract: The invention relates to a leaf assembly (102) for a multi-leaf collimator, comprising a leaf frame (104) and a plurality of leaves (106) for shielding beams (108) from a selected area, wherein the leaves (106) are arranged sideways and adjacently in the leaf frame (104) for shielding beams (108) being emitted from a radiation source (110) located above the assembly (102), wherein each leaf (106) is mounted in the leaf frame (104) displaceably in an adjusting direction (112) being oriented perpendicularly related to said beams (108), and wherein the leaf frame (104) provides a linear guidance (114) for each leaf (106) within the adjusting direction (112), being designed in a such a way that the leaf frame (104) is adapted to allow for lateral movement of the leaves (106) superposing said linear guidance (114), thus allowing mutual abutting of the leaves (106).

Abstract: The invention relates to a leaf module (102) for a multi-leaf collimator (132), comprising a leaf unit (104) and a leaf drive unit (106), wherein the leaf unit (104) comprises a leaf (108) for shielding beams from a selected area, and the leaf unit (104) is mounted displaceably in an adjusting direction (110), wherein the leaf drive unit (106) is designed to displace the leaf unit (104) linearly in the adjusting direction (110), and wherein the leaf drive unit (106) comprises at least one drive mechanism (112), being designed in such a way that the drive mechanism (112) operates based on pneumatic actuation. Furthermore, the invention relates to a multi-leaf collimator (132) comprising a plurality of leaf modules (102) according to the invention. The invention is based on the objective of designing a leaf module (102) and a multi-leaf collimator (132) as compactly as possible, while achieving a simple, reliable and variable adjustability of the leaf unit (104).