The current status of bone scintigraphy in malignant diseases.

For the past few decades, planar bone scintigraphy has been the most frequently performed imaging study in the evaluation of metastatic bone disease. Although scintigraphic findings alone are often nonspecific for skeletal pathologies, this technique reportedly has an exquisite sensitivity. However, recently accumulated data on the efficacy of positron emission tomography with fluorine-18 fluorodeoxyglucose and fluorine-18 sodium fluoride as well as magnetic resonance imaging for evaluating skeletal metastatic disease now indicate that conventional planar bone scintigraphy is not very sensitive in the detection of metastatic bone lesions in selected malignancies. Nevertheless, bone scintigraphy still remains the primary imaging modality for evaluation of metastatic bone disease owing mainly to its cost effectiveness and wide availability. In addition, recently introduced hybrid imaging systems combining single-photon emission computed tomography and spiral computed tomography, although not widely available yet, increase considerably both the sensitivity and specificity of bone scintigraphy. This article focuses primarily on the current role of bone scintigraphy and its strengths and weaknesses in assessing different types of malignant diseases relative to other imaging modalities in selected malignancies.