Radio-guided surgical biopsy for the diagnosis of suspected osseous metastases.

Radioisotope bone scanning is frequently employed in staging malignancies. However, false positive results are common, and biopsy is usually required. In the absence of plain radiographic abnormalities or local symptoms, localization of the area of abnormal tracer activity at the time of open rib or sternum biopsy may be difficult. It often requires resection of a large portion of one or more ribs or other bones to assure that the target area was biopsied, and still the area in question is commonly missed. In this setting, the newly-developed, small gamma probe is now used as a tool to allow precise intraoperative localization of increased tracer activity in the target bone. The use of gamma counting is an easy, highly accurate aid (100% sensitivity) to localize areas of abnormal radioisotope uptake in suspected asymptomatic osseous metastases, usually for open biopsy of a rib. The use of this technique obviates the need to obtain intraoperative localizing radiographs to confirm accurate rib identification, thereby substantially decreasing operative time.