[Value of the "region of interest" technique in the scintigraphic diagnosis of primary bone tumors (author's transl)].

Employing ROI-technique, a ratio Q was obtained from relating accumulation of 99mTc-MDP at the site of the bone lesion (n = 150) with that of contralateral non-involved osseous areas. Values of Q were correlated with histologic tumor diagnosis, its dignity and frequency. Values of Q of greater than 3.0 were found in 95% of all sarcomas, in 100% of the osteosarcomas but in only 3.8% of all benign bone tumors. Values ranging from 1.0 to 1.2 were exclusively measured in benign tumors (e.g., in 52% of juvenile bone cysts and in 67% of non-ossifying fibromas). Since the threshold--separating benign from malignant lesions--at Q = 3.0 was blurred by tumorlike lesions, metastases and especially by Paget's disease, this method does not precisely predict dignity. However, this method may complement radiographic evaluation with low values supporting the diagnosis of a benign lesion. The combined findings of radiography and these rations gained by nuclear imaging may help determine the pathway of a patient through further diagnosis and treatment.