Dosimetry of a new holding device for fast d (14) + Be-neutron irradiation of human xenografts in nude mice.

Fast neutron irradiation of human xenografts in the flanks of nude mice is mainly a technical problem. The feasibility is dependent on the distribution of the tumor absorbed dose DT and on an effective shielding of the bodies of the animals. Therefore a special holding device for simultaneous irradiation of two tumour-bearing animals was developed. Meticulous dosimetric investigations using TLD-300 detectors in a mouse phantom showed that a relatively homogeneous dose distribution could be achieved in the xenografts and that effective shielding of the mice from direct irradiation would be achieved; the dose for the bodies of the animals being less than 10% of the dose to the tumour. Thus survival and a sufficient follow-up period of the irradiated animals could be guaranteed for all preclinical dose ranges used.