Dosimetry in a myeloablative setting

In clinical therapy trials using high dosages of systemically administered radioactivity to treat cancer, myeloablation may occur. This is either an effect of the circulating radioactivity labeled to antibodies exposing the bone marrow to radiation, or it may occur because malignant cells in the bone marrow are targeted. Bone marrow cells may be targeted through antigens expressed on cells in the bone marrow or because radioactivity is targeted to the skeleton. Assessment of radiation absorbed dose to the marrow may be useful for dose escalation or individualized patient treatment planning. With successful preservation of marrow function with autologous marrow or peripheral blood stem cell transplantation, other normal organs may also receive sufficient radiation to show toxicity. Accurate dose estimates to these organs is important for the design of future studies in order to minimize or avoid toxicity. This paper reviews internally administered high dose radiation therapy studies, and examines the radiation absorbed dose estimates reported from these studies.