Bone Scanning with 85Sr, 87mSr and 18F. Physical and Radiopharmaceutical Considerations and Clinical Experience in 50 Cases

Abstract

Abstract Physical and radiopharmaceutical considerations have shown the advantages of short-lived isotopes in enabling us to scan with reduced radiation dose. Simple methods of producing 87mSr and 18F in a nuclear reactor, and of preparing them for injection are described. There is little to choose between these two isotopes. 87mSr, however, has certain physiological advantages especially when scanning the pelvis. The choice of time interval has been discussed. With 87mSr the best scans were obtained approximately one hour after administration. Clinically, our cases fall into three groups. First, primary neoplasms; there are eight of these. Demonstrable adjacent bony involvement in connection with a soft tissue malignant tumour (e.g. Pancoast's tumour) will affect the approach to treatment. Secondly, 38 cases of metastic bone lesions are analysed in relation to radiographic changes. Positive scans influence the decision concerning treatment of the primary lesion if not already initiated. Scanning gives a more accurate and earlier assessment of radiotherapy field size than does the radiograph in both primary and secondary bony lesions. Negative scans give reassurance to patient and clinician. The third group consists of bony dystrophies and infective lesions. One case in which a sarcoma had developed is common to the first group. We hope that we may eventually distinguish stages in bone dystrophies.