Dose Evaluation of Esophageal Cancer Treatment by the Multiple Radiation Beams of Co-60 Gamma Rays

Keimyung Medical Journal 1987;6(2):353-357.

코발트-60 감마선의 다문선속에 의한 식도암치료의 선량 평가

최태진; 김옥배; 서수지

Abstract

CT technique was used to provide tumor depth; lung thickness and tissue density for the ■calculation of delivered radiation dose' to various points on the esophagus;: spinal cord and interest points of lung tissue. In treatment planning; in order to avoid excess dose at the spinal cord; we ■usually set the prone position of patient. The angle of the incidence beams were used for three portals: LPo; RPO and AP. The percentage depth dose changes by the inhomogeneity of Various tissue structures; such as lung; mediastinum and other thoracic contents. Therefore the correction factor of 4% increase should be applied as being with 1cm of lung tissue in Co-60 gamma radiation therapy. With known accuracy of the CT representation of the RANDO section; the treatment planning was computed to predict the dose to a point in the same section which was selected as representative of normal esophagus location in the TLD measurements in the phan torn studies.