one of the underlying observations that makes the methods disclosed herein so useful is that patients having bone marrow involvement are particularly susceptible to radioimmunotherapy when the radiolabeled antibodies are targeting cells in the bone marrow radioisotopes in the bone marrow ablate normal progenitor cells which may not even express the targeted cell surface molecule thereby depleting the population of immune cells which would normally facilitate reconstitution of the immune system following radioimmunotherapy moreover patients who do have bone marrow involvement do not benefit from autologous bone marrow harvest and transplantation since such transplantation merely reinfuses tumor cells back into the patient thus having a routine method whereby bone marrow involvement is identified and rectified prior to radioimmunotherapy would be a valuable addition to the field of lymphoma treatments in this regard the clinical parameters disclosed herein would likely also indicate the extent of bone marrow toxicity experienced by antibodies labeled with other cytotoxic moieties e g toxins thus the parameters disclosed herein may also be used to predict and deter toxicity and bone marrow ablation due to administration of cytotoxic antibodies the methods of the present invention may be used to treat a variety of cancers particularly b cell lymphomas and leukemias but are particularly useful wherein said b cell lymphoma is non hodgkin 39 s lymphoma nhl rituximab u00ae has already been approved for the treatment of low grade follicular nhl but the present inventors have surprisingly found that rituximab u00ae is also beneficial for the treatment of intermediate and high grade nhl including bulky disease accordingly the lymphomas which are treatable by the methods of the present invention include low grade follicular non hodgkin 39 s lymphoma.