Computed tomography in detecting bone metastases of breast carcinoma. Is it better than plain x-ray?

OBJECTIVE To compare 5mm slice computerized tomography (CT) and conventional x-ray (XR) in the detection of bone metastases in breast carcinoma patients. METHODS Ninety-eight female breast cancer patients treated in Ankara Oncology Hospital, Ankara, Turkey between September 1997 and March 2002 were assigned into 3 groups with respect to their Tc bone scan (Sc) results. Group 1 included patients with overt bone metastases, group 2 included patients with suspicious of metastases and group 3 were those patients with normal Sc results with back pain complaint. All patients underwent XR, and 5mm contiguous slice CT imaging for the related metastatic sites. For the third group, lumbosacral region was examined. RESULTS A total 33 bone metastases have been diagnosed out of 98 patients. The Sc result showed 26/33 metastatic cases, XR 19/33 and CT 22/33 cases. There were no false positive results for CT and XR. Results of CT have 11 and XR has 14 false negatives out of 33 metastases. For XR the calculated sensitivity was 65.6, specificity was 100, diagnostic accuracy was 88.7, whereas for CT, sensitivity was 71.8, specificity was 100 and diagnostic accuracy was 90.8. When CT and XR were compared to detect bone metastases, results were not statistically significant (p>0.05). CONCLUSION Our results suggest that 5mm slice CT is not superior than XR to detect metastatic bone lesions. Larger series comparing different slice thickness of CT are needed to clarify the issue.