Is the anterior bone scan necessary in the diagnosis of osseous metastases?

Bone imaging studies of 1650 patients with known or strongly suspected extraosseous malignancies were reviewed to determine whether a completely negative posterior view was sufficient to exclude metastatic disease. Of 708 negative posterior images, 27 (3.4%) were positive for metastasis on anterior views. All of the anterior lesions were in the sternum, sternoclavicular joints and first four ribs. When the posterior view is positive, further views may be unnecessary. Negative or equivocal posterior images necessitate anterior views of the thoracic cage.