[Diagnosis of occult skeletal metastasis: alkaline phosphatase versus skeletal scintigraphy]

In this study the value of alkaline phosphatase activity was compared with the bone scintigram in detection of clinically occult bony metastasis amongst a group of 400 cases histories of cancer patients. For bone scanning a sensitivity of 96% and a specificity of 94% were detected, among the unsuspected scans, only 1% bony metastasis was demonstrated. For the levels of alkaline phosphatase a sensitivity of 74% and a sspecificity of 85% were demonstrated, with normal levels only in 4% bony metastasis were detected. The true positive elevated levels of alkaline phosphatase in 43% of cases normalised within two months. It is implicated that controlling tumor patients by bone scanning may be substituted by short term determination of the level of alkaline phosphatase in the practice of general practitioners.