Medical apparatus and systems, namely, x-ray tubes and housings therefor used for diagnostic, therapeutic and radiographic purposes; medical charged particle accelerators used in radiotherapy and computer software embedded therein for use in the field of radiotherapy; industrial linear accelerators used in industrial imaging; medical linear accelerators used in radiotherapy and computer software embedded therein for use in the field of radiotherapy; patient positioning tools; radiation beam collimation apparatus for conformal beam radiotherapy; imaging and treatment simulation apparatus for treatment planning and simulation; x-ray radiographic and fluoroscopic imaging systems comprised of a receiver/transmitter panel and a display; x-ray imaging systems that convert radiation into digital signals comprised of receiver/transmitter panels, user interface computers, displays, and embedded software for use in the field of x- ray imaging; and medical devices for delivery of radiation from within the patient such as remote afterloaders for brachytherapy and brachytherapy wire and needle positioning apparatus and computer software embedded therein for use therewith