Chromosome aberrations induced in patients treated with chemotherapeutic drugs and irradiation for acute lymphatic leukemia.

Chromosome analyses were carried out in lymphocytes of ten children with ALL, prior to and during combined therapy with antineoplastic drugs and cranial irradiation. Chromosome preparations from group I (four patients) were analysed by conventional staining. For group II (six patients) the FPG technique (fluorescence plus Giemsa) was applied after BrdU treatment of cultures and cells were scored exclusively in first division. A significant clastogenic effect could not be detected in samples collected during or after chemotherapy for either group. After cranial irradiation of those patients in group II. linear dose-effect relationships for dicentric plus ring chromosomes, and for excess acentrics, could be demonstrated after correction for the relative amount of irradiated volume.