Bone scanning in carcinomas of the colon and rectum.

Bone scanning has been shown to have a higher rate of accuracy in diagnosing osseous metastatic lesions from carcinomas of the lung and breast. In the present report, we have demonstrated this to be true for osseous metastases from carcinomas of the colon and rectum. We found that a high percentage (75%) of patients who have pelvic or back pain have positive 99mTc bone scans for metastases in spite of the negative radiographs. The previously reported incidence of 5-6% of osseous involvement from these tumors is probably lower than the actual incidence, as these studies were reported without the benefit of bone scanning.