Cancer comprises a group of diseases characterized by the uncontrolled grow
th of abnormal cells that spread from the anatomical site of origin. For ma
ny types of cancer, surgery alone has proven inadequate, necessitating a br
oader approach to treatment incorporating chemotherapy and radiotherapy. Of
particular recent interest has been the use of alpha-emitters in the treat
ment of microscopic carcinoma. The effective application of these materials
requires an understanding of the physical and biological bases of radiatio
n therapy. In addition, both radiochemical and radionuclidic purity are ess
ential in all clinical applications. Recent work with the alpha-emitting ra
dionuclide bismuth-212 offers considerable promise in the treatment of micr
oscopic ovarian carcinoma resistant to conventional treatment modalities. O
ngoing improvements in methods for its preparation are expected to further
improve its therapeutic utility.