Experiences with bone scanning in differential diagnosis of local bone lesions

Because some primary tumours often metastasize to the skeleton, their early detection is essential for further therapy and prognosis. Radiographic examination is not sufficiently sensitive for early detection of bone metastases, because it can reveal the typical sign of metastases--decalcification--only after loss of 30-50% of the original amount of calcium from bone tissue (18). Bone scanning with bone-seeking radiopharmaceuticals represents a viable technique for early detection of bone lesions, especially early metastatic disease. The indication for this examination is undoubtedly in breast cancer, cancer of prostate, lung, thyroid gland, hypernephroma, melanoma, plasmocytoma and malignant lymphomas. After good clinical experience of the authors with bone scanning in detection of secondary bone tumours in known primary localisations (9, 14, 15, 10), they tried to elaborate in this paper indicative criteria for bone scanning in patients with suspicious secondary tumourous lesions by unknown primary localisations.