Application of computerized tomography to radiation therapy and surgical planning

Computerized tomography (CT) which permits imaging the internal anatomy in axial cross section, has had a major impact in medicine, primarily in the diagnostic area. The CT scans are also useful in determining the extent of disease which is important in selecting the appropriate therapy. For therapy, the CT scan is becoming important in planning a course of radiation therapy for a cancer patient and to a lesser extent, in planning a surgical reconstruction for some patients. For both of these treatment modalities it would be desirable to have a three-dimensional reconstruction of the internal anatomy. This paper discusses the use of a three-dimensional perspective of the internal anatomy, obtained from multiple CT scans, as a guide to these two therapeutic modalities.