DOSE EVALUATION OF PATIENTS RECEIVING TOTAL-BODY IRRADIATION FOR THE PRETREATMENT OF BONE-MARROW TRANSPLANTATION

In a total-body irradiation (TBI), an absorbed dose of around 10 Gy is given to a patient with leukaemia within a couple of days. Delivery o f a homogeneous dose throughout the whole body is difficult, and usual ly requires sophisticated irradation techniques. It is important to ev aluate patient doses experimentally both for physical treatment planni ng and radiological protection. Organ and surface doses of patients we re evaluated for a newly employed TBI technique - a modified tracking technique. An experiment with a RANDO phantom demonstrated a good dose distribution over the whole body. Measurement of patient doses, howev er, revealed a variation of the doses between patients. Reproducibilit y of patient set-up is considered to be a critical factor for the vari ation, and improvement is desirable in this regard.