Diagnostic value of whole-body MRI and bone scintigraphy in the detection of osseous metastases in patients with breast cancer - a prospective double-blinded study at two hospital centers

The purpose of this study was to compare the diagnostic accuracy of whole-body MRI (WB-MRI) and bone scintigraphy (BS) for the screening of bone metastases for the first time in a large and homogeneous patient collective with breast cancer in a systematic and controlled study. 213 breast cancer patients were evaluated for bone metastases under randomized, double-blinded and prospective conditions at two hospitals. All participants were examined by WB-MRI and BS over an average period of four days. The examinations were performed separately at two different locations. The WB-MRI protocol included T 1-TSE and STIR sequences. WB-MRI and BS were reviewed independently by experienced radiologists and nuclear medicine specialists in a consensus reading. In 66 % of cases bone metastases were excluded by both procedures, and bone metastases were detected concordantly in 2 % of cases. In 7 % of cases there were discrepant results: in 7 cases BS was false-positive when WB-MRI was negative. In 5 / 7 cases BS was negative when WB-MRI identified bone metastases. In 89 % of cases BS was uncertain when WB-MRI was true-negative. In 17 % of cases WB-MRI showed important (non-) tumor-associated findings. The sensitivity, specificity, positive and negative predictive value and diagnostic accuracy for WB-MRI were 90 %, 94 %, 82 %, 98 % and 99 % and for BS those were 40 %, 81 %, 36 %, 91 % and 93 %. (orig.)