Quality assurance in radiotherapy--a clinical view-point

Despite the advanced treatment methods now available, the total result in 5-year survival is 40-50% of all patients with malignancies and 20% of these patients will have the chance of a 10-year survival. In the course of their disease a radiotherapy is indicated in about 2/3 of all cancer patients. Thus, radiotherapy makes quite a considerable contribution to the qualitative improvement of the treatment of patients with malignancies. Eradication of the tumor and protection of normal tissue can be only a compromise between tumor control and the production of complications. For the risk assessment of radiotherapy, the steepness of dose-response curves is of paramount importance. That means, small errors in defining and delivering dose can have catastrophic results in terms of failure to control the patient's disease and, on the other side, in terms of complications, that means in quality of life. Although the costs of therapy, in absolute values, vary from one country to the other, it can be stated in rough approximation that a failed radiotherapy will make rise the costs by a factor of 3. Proceeding on the fact that in 30-40% of patients, who received radiotherapy, the initial treatment failed to control the primary disease, the enormous additional costs involved become obvious, not to speak of the main argument--the regrowth of the patient's tumor. For the improvement of this situation quality assurance (QA) is an essential prerequisite, which should be guaranteed in all successive steps of radiotherapy. In the paper an analysis is given for all individual steps in the chain of radiotherapeutic measures.(ABSTRACT TRUNCATED AT 250 WORDS)