ESTIMATION OF THE RADIATION-DOSE DELIVERED TO ANY POINT OUTSIDE THE TARGET VOLUME PER PATIENT TREATED WITH EXTERNAL-BEAM RADIOTHERAPY

The methodology we have developed to study dose distribution outside t he target volume during external beam radiotherapy allows us to determ ine the dose received by the patient arising from leakage radiation an d scattered radiation from both the head of the treatment machine and from the treatment room. It also allows us to evaluate the dose due to photon scattering in the patient by means of a dedicated 3-D algorith m permitting computations for the whole body of the patient and taking into account height, sex and anatomical data at the time of the treat ment, dosimetric data and lung heterogeneity parameters. This methodol ogy offers solid criteria for recommendations concerning radiation pro tection.