Metastatic bone disease: evaluation by functional imaging in correlation with morphologic modalities

The diagnosis of presence, location and load of metastatic, bone involvement has important implication on patient management and prognosis. This requires collection of data obtained using different imaging modalities. Bone scintigraphy is a highly sensitive and cost-effective screening modality. However, to overcome its lower specificity and its limitation in evaluation of vertebral metastases, CT, PET or MRI can be utilized to verify the nature of suspicious lesions. Expansion of SPECT/ CT may fine tune the highly sensitive bone scintigraphy. PET has an emerging and leading role in many tumors, occasionally obviating the need for bone scintigraphy, particularly in evaluation of response to therapy. PET and whole body MRI offers a potentially important tool to provide the earliest clue of bone marrow metastasis. The value of F-18 PET as a sensitive bone imaging tool needs to be further evaluated on a larger scale in different setting including treated and untreated cancer patients and to evaluate also whether potentially better resolution would lead to more benign lesions detection mimicking metastasis such as fractures, inflammatory, infection, and degenerative involvement of bone. The added value of PET-CT is also to be further examined with this regard.