The value of bone marrow scintigraphy using 99mTc monoclonal antigranulocyte antibodies in complement to bone scintigraphy in detecting bone metastases from primary breast cancer

This prospective study evaluates bone marrow scintigraphy (BMS) in detecting bone metastases from primary breast cancer when performed in complement to conventional bone scan (BS). Sixty women predominantly with low-stage disease underwent BS followed by BMS within 1-35 days using BW250/183 antigranulocyte antibodies. A receiver operating characteristic (ROC) analysis was performed to compare BS to BS+BMS on a patient-by-patient basis using a ‘gold standard’ composed of subsequent computed tomography, magnetic resonance imaging, X-ray or BS examinations and at least a 12 month follow-up. Metastases were present in eight out of 60 patients (13%). Specificity was improved by BS+BMS compared to BS alone (90%, 65%) as well as positive predictive value (62%, 27%), accuracy (87%, 72%), positive (10.4, 2.4) and negative (0.20, 0.00) likelihood ratios. Sensitivity (100%, 88%) and negative predictive value (100%, 97%) were similar for BMS+BS and BS alone. As a result of BMS, clinical management was modified in 15 patients (25%). In conclusion, BMS supplements BS by improving specificity, positive predictive value and accuracy in detecting breast cancer bone metastases. The ROC curves show improved specificity for BS+BMS at the same sensitivity compared to BS alone. Consequently, BMS may be useful in low-stage subjects with positive or equivocal BS for metastases.