Abstract: A dynamic table/shield apparatus contains a movable treatment table and at least one shielding block which is movable relative to the table. The apparatus effects total body irradiation treatment of a body disposed on the table while completely shielding, throughout the treatment time, a midplane of a predetermined body part from a radiation beam emitted from a radiation source during the treatment. During the treatment, the table and body are moved in a first direction at a first velocity V.sub.1 through a radiation field, and the shielding block is moved relative to the table at a second velocity V.sub.2 in a second direction opposite of the first direction. The second velocity is equal to (V.sub.1)(b/a), wherein "V.sub.1 " is the first velocity, "b" is the perpendicular distance between the the shielding block and the midplane of the body part, and "a" is the perpendicular distance between the midplane of the body part and the radiation source.