Fundamentals, trends and our experiences with total body irradiation (TBI) before bone marrow transplantation (BMT).

At the end of the sixties and to beginning of the seventies years the total body irradiation (TBI) was introduced in the concept of bone marrow transplantation (BMT). The aim is the destruction of leukaemic or normal stem cells surviving the chemotherapy or the overcoming of the immunological defense. From March 1980 to January 1987 we have treated 84 patients with single exposure of 8.5 to 10.5 Gy midline dose for body and lung in cases of leukaemia and of 6 to 7 Gy for patients with aplastic anaemia. We used a dose rate of about 5.5 cGy/min delivered by a linear accelerator. The results were comparable with other centres but a further indicator for the effectiveness of a irradiation technique is also the idiopathic interstitial pneumonitis (IIP). Our incidence of IIP was 10.7 per cent and the mortality was 2.4 per cent. Additional we have had 8.3 per cent interstitial pneumonitis (IP) caused by an infection. All patients with a combination of IP and GVHD had a fatal prognosis. In present time a tendency is to see to fractionation techniques in total body irradiation for decreasing of the pneumonitis rate, the reduction of severe acute and delayed side effects, for a better homogenisation of the dose in the whole body and for using of synchronizing effects on the stem cells.