[Comparison between traditional skeletal radiography and total body bone scintigraphy in the diagnosis of multiple myeloma].

28 patients with multiple myeloma were examined by skeletal x-ray and 99Tcm-diphosphonate bone scan. Using both techniques, a total of 70 myelomatous bone lesions was found in 13 (46,5%) of the 28 patients: 69 bone lesions were detected by radiography and 33 by radionuclide imaging. Results indicate that x-ray is superior to bone scan, approximately twice, in detecting myeloma-related bone lesions. The low sensitivity of bone scan in myeloma can most likely be explained by the particular nature of myelomatous bone lesions. Multiple myeloma is almost always osteolytic, with very little new bone formation and extensive osteoclast activity related to osteoclast activating factor, whereas skeletal uptake of 99Tcm-diphosphonate seems to be related mainly to osteoblastic process. An exception to this general finding is the rib fractures, in which the two methods are equally reliable. These findings suggest that radiography is the method of first choice in obtaining a skeletal survey in patients with multiple myeloma.