BONE MARROW UPTAKE OF ^99mTc SULFUR COLLOID AND MARROW SCINTIGRAPHY IN THE EARLY DIAGNOSIS OF EXPERIMENTAL METASTATIC BONE TUMOR

Abstract

Metastasis to bone of malignancy can not be recognized on the skeletal radiographs until 30 to 50% of decalcification is attained by direct bone destruction and accompanying bone absorption. This would require a sufficiently long time, and delay an early recognition of the lesion. The initial lodgement of tumor cell occurs in the active marrow, and the tumor would evade the cells of the reticuloendothelial system as it grows and invades the surrounding tissue. This is expected to be recognized on the bone marrow scintigrams earlier than the radiographs, and hopefully bone scans when appropriate radiocolloids are employed. The present investigations were undertaken in order to know the best preparation kit of ^99mTc sulfur colloid commercially available at the moment, and to explore the possibility of early diagnosis of bone metastasis by bone marrow scinitigraphy employing that colloid. (a) Marrow scintigrams depicted the metastatic bone lesions at the time of positive bone radiographs, and (b) they were indicative of lesions even when the bone scans and radiographs were negative. These results indicate that the bone marrow imaging would permit diagnosis of bone metastasis earlier than the bone scans and radiographs.