Abstract

Widespread implementation and continuing improvements in computer technology led to the development of modern radiotherapy, called Three Dimensional Conformal Radiotherapy. Using CT scan or MRI scan it’s now possible to define target volume in three dimensions using delineation on multiple slices from computer tomography or other imaging study. The information from these scans feeds directly into the radiotherapy planning system. The computer programme then designs multiple radiation beam directions to crossfire on the targets. Individual beams are shaped or intensity modulated to create dose distributions that conform to ‘conform’ more closely to the shape of the tumour and avoid healthy tissue as far as possible. Patient positioning, immobilization, and treatment delivery become also computer controlled and to great deal automated, so that setup errors and patients motions are minimized. That enables to maximize dose to tumors, minimize dose to surrounding tissues, and in so doing, improve the likelihood of malignant diseases control and outcome, and patient’s better quality of life.

Key words: computer technology, conformal radiotherapy, three dimensionally planning