Patent Number: 
Section: claims

1. A modular shielding structure for radiation protection in a radiotherapy room comprising:at least one wall structure comprising at least two rows;the first wall row comprising a row of base modules including first and second base modules aligned along a common longitudinal axis in a sliding relationship such that a front face of a first base module and a rear face of a second base module abut, where further base modules are arranged to maintain the pattern of face abutment established by the first and second base modules until a row of predetermined length and where a bottom row of complementary modules are positioned to fill any gap on a lower side of a base module row;second and subsequent wall rows comprising the arrangement of the first wall row placed on top of or adjacent to the first wall row successively and up to a desired wall height such that bottom surfaces of second or subsequent wall rows abut top surfaces of a preceding wall row;a second wall base module aligned such that a longitudinal axis of the second wall base module is perpendicular to that of a wall base module located in a lower corner of the wall;a front face of a second wall base module is contacting a first top row of complementary modules filling a gap on an upper side of a wall top; andwherein, said base modules comprise two identical cuboids fused together, each of these cuboids having equally sized front and rear faces connected with four rectangular sides comprising left, right, top, and bottom sides and being positioned in parallel, side-by-side, along mutually facing rectangular side and where the cuboids are also mutually offset vertically and horizontally; andwherein, said complementary modules comprise a single cuboid having equally sized rectangular front and rear faces connected with four rectangular sides comprising left, right, top, and bottom sides, the complementary modules having top and bottom edges equal in length to the length of the edges of base module faces and side edges one half the length of the edges base module faces, and the complementary modules comprise top and bottom sides equal in dimension to the dimensions of the sides of base module cuboids, left and right sides with length equal to the lengths of complementary module top and bottom sides, and widths equal to the dimension of side edges of complementary module faces. 2. The modular shielding structure of claim 1, further comprising second wall structure, the second wall structure comprising plural base modules and plural complementary modules, the second wall structure arranged perpendicular a first wall structure and comprising second wall structure base modules perpendicular the first wall structure base modules and in contact with first wall base modules such that the second wall structure base module faces abut the sides of the first wall base modules; andwherein the second wall structure comprises the same components and basic arrangement of the wall structure of claim 1 such that the second wall structure is composed of sufficient base modules and complementary modules to have a desired height. 3. The modular shielding structure of claim 1 further comprising each of said base modules and complementary modules are made of metal casing and filled internally with metal powder.