Clinical and physical aspects of total body irradiation for bone marrow transplantation in Nijmegen.

Eighty-nine patients were transplanted with allogeneic bone marrow after a standard conditioning regimen consisting of cyclophosphamide and fractionated total body irradiation (2 x 4.5 Gy) with average dose rates of 4.1 and 12.3 cGy/min, respectively. The average rectum and lung dose was 9.2 +/- 0.45 and 7.5 +/- 0.78 Gy. In vivo dosimetry was performed in 71 patients irradiated with 18 MV X-rays from left and right lateral. Forty-three patients (48%) died. After increasing the dose rate the incidence of interstitial pneumonitis increased, but the number of relapses decreased.