Prospects of computed tomography in radiation therapy.

Computerized tomography has become an essential element in the staging of tumors and in the localization of the tumor and neighboring normal tissues for treatment planning. It offers the potential for more accurate delivery of higher doses with improved therapeutic ratio, for the identification of and correction for tissue inhomogeneities, and for three-dimensional treatment planning. For treatment planning purposes only minor changes are required in the current generation of scanners. Possibilities for the future include dynamic radiation treatment, combined CT scanners, simulators, and treatment planning computers, and a potential for significant cost saving through improvements in the results of cancer therapy.