Absent or faint renal uptake on bone scan. Etiology and significance in metastatic bone disease.

A review of 14,296 unselected bone scans identified 889 scans showing absent or faint renal uptake. The majority of cases were associated with renal insufficiency (816/889; 91.8%), while widespread metastatic bone disease was the most common cause in a group of patients without renal disease (53/889; 6.0%). Of the 140 patients with prostate cancer, 108 (77.1%) had evidence of bone metastasis, 19 of whom (17.6%) revealed absent or faint renal uptake, demonstrating that poor renal uptake is more frequently associated with prostate cancer than with any other malignancy. Of note was that 162 out of 328 (49.4%) patients with stomach cancer at varying stages showed evidence of bone metastasis, and 14 of them (8.6%) showed poor renal images on bone scan. Interestingly, ankylosing spondylitis and rheumatoid arthritis were occasional causes of lack of renal activity (4 and 3 cases, respectively). A case of adult-form osteopetrosis, showing strikingly increased uptake mainly in the long bones with markedly diminished renal uptake, was also included in this study. Of the 53 bone scans with metastatic disease showing poor renal uptake, 44 (83.0%) revealed evidence of diffuse or multiple metastases in both spine and ribs, while 49 (92.5%) showed malignant involvement in three or more regions and 35 (66.0%) in four or more regions, suggesting widespread bone involvement in most cases.