Detection of bone marrow involvement in patients with cancer

Current methods for the study of bone marrow to evaluate possible primary or metastatic cancers are reviewed. Bone marrow biopsy, radionuclide scan, computed tomography and magnetic resonance imaging (MRI) are analyzed with regard to their clinical usefulness at the time of diagnosis and during the course of the disease. Bone marrow biopsy is still the examination of choice not only in hematologic malignancies but also for tumors that metastasize into the marrow. Radionuclide scans are indicated for screening for skeletal metastases, except for those from thyroid carcinoma and multiple myeloma. Computed tomography is useful for cortical bone evaluation. MRI shows a high sensitivity in finding occult sites of disease in the marrow but its use has been restricted by high cost and limited availability. However, the future of MRI in bone marrow evaluation seems assured. MRI is already the method of choice for diagnosis of multiple myeloma, when radiography is negative, and for quantitative evaluation of lymphoma when a crucial therapeutic decision (i.e. bone marrow transplantation) must be made. Finally, methods are being developed that will enhance the sensitivity and specificity of MRI studies of bone marrow.