[en] Bone scanning with Tc-99m MDP was performed in 52 patients with spinal metastases of breast cancer. According to patterns of RI distribution on 159 bone scans, metastatic spinal tumor (MST) was staged as follows: (1) stage I - RI uptake limited to the spine or invading the ribs, (2) stage II - uptake invading the pelvis, cranium and sternum, (3) stage III - uptake invading the bone of the extremities, clavicula, and scapula. With the use of this staging, three-year survivals after the diagnosis of MST were examined in 45 patients. Among patients with metastases to the lungs, pleura, liver, and brain, three-year survivals were low, irrespective of stages; whereas significant differences in the survivals for patients without metastases to these sites were seen among stage groups. Bone scan staging may give a guideline as to whether surgery for MST is indicated. (Namekawa, K.)