CLINICAL APPLICATION OF ON-LINE PORTAL IMAGING SYSTEM IN RADIOTHERAPY

Accurate delivery of prescribed dose to the target volume in radiotherapy is only possible by appropriate positioning of patient during subsequent treatment sessions. Conventional portal film or on-line portal imaging systems are used for this purpose. Portal imaging system allows on-line adjustment of patient set-up during treatment, rather than the retrospective corrections which can be made using conventional portal films. Instantaneous imaging and a rapid quantitative comparison of the difference at set-up are the advantages of this system. In this paper the applications of on-line portal imaging system at our department is presented.