A variable speed translating couch technique for total body irradiation

We have developed a variable speed translating patient couch system for the delivery of total body irradiation (TBI), For a whole body Rando-type phantom, dose variation at mid-plane relative to the prescription point (navel) can be as high as 15% (neck or legs) with a constant velocity. By taking into account variations in body thickness, the intensity modulation radiation therapy, resulting from variable velocities, effectively delivers a uniform dose distribution at mid plane. The couch control user interface, technical aspects and dose planning optimization procedure for determining velocity distribution are described. (C) 2000 American Association of Physicists in Medicine. [S0094-2405(00)04005-0].