Can Treatment With Bismuth Reduce Toxicity to Chemotherapy and Radiotherapy?

Inclusion Criteria: * Patients of 18 years or over referred to the Department of Haematology L, Herlev Hospital, with a view to 'cytostatic'? treatment of or radiotherapy for haematological malignancy Exclusion Criteria: * Pregnant women and nursing mothers * No informed consent from patient * Known hyper sensitivity to bismuth or other tablet content * Severe renal insufficiency with creatinin clearance below 25 ml/min. * Patients receiving other treatment for protection of the mucous membrane except cryo treatment of the oral cavity (lumps of ice in the mouth) * Other experimental treatment within past four weeks.