Best for breasts: 99mTc sestamibi or 99mTc oxidronate?

Abstract

Aim: The aim of this study was to compare 99mTc sestamibi and 99mTc oxidronate in patients with either equivocal or indeterminate triple assessment or for evaluation of co-existent disease in known breast cancer appearing suitable for management by wide local excision. Method: One hundred patients (199 breasts) underwent scintimammography with both 99mTc sestamibi and 99mTc oxidronate, with a maximum of 6 days between studies. Four experienced, ‘blinded’ observers scored each digital image on a scale of 1 (normal) through 3 (equivocal) to 5 (definitely malignant). Images were also ‘consensus’ reported by two observers aware of each patient's clinical history. Results: Sensitivity, specificity and ROC curves were calculated for each observer. ROC curves for each of the ‘blinded’ observers were significantly different from the ‘consensus’ observers for both 99mTc oxidronate (P=0.001) and 99mTc sestamibi (P=0.02). However, only borderline significant difference (P=0.04) exists between the ‘consensus’ ROC curves when scoring 99mTc sestamibi (sensitivity 87%, specificity 90%) or 99mTc oxidronate (sensitivity 90%, specificity 90%) images. Conclusions: Scintimammography, using either 99mTc sestamibi or 99mTc oxidronate, has high sensitivity, specificity and accuracy in the diagnosis of primary breast cancer. Although 99mTc sestamibi scintimammography is significantly better than 99mTc oxidronate scintimammography for ‘blind’ reporting, there is little difference in a ‘consensus’ clinical reporting context.