Treatment planning using images of regret

The lack of well-defined criteria for evaluating alternative treatment plans introduces a degree of subjectivity into the planning process. The complexity of conventional isodose charts causes further difficulty in making rapid and reliable evaluations of a plan. An objective method is described, using a prescription file to define the clinician's requirements in terms of the area of each organ which may be treated to predefined tolerance doses. The computer program OSCAR then compares the predicted dose distribution with the prescribed limits, and displays regions of noncompliance as colored "areas of regret." In addition, score functions are used to provide a quantitative measure of the acceptability of dose distributions within the target and each organ at risk. An example is described in which a plan for the treatment of ca esophagus is evaluated using both images of regret and score functions.