Breast cancer: monitoring response to neoadjuvant chemotherapy using Tc-99m sestamibi scintimammography.

BACKGROUND Aim of the study was to assess the value of scintimammography using Tc-99m sestamibi in the evaluation of tumor response to neoadjuvant chemotherapy. MATERIAL ANS METHODS: Results were calculated for 9 patients undergoing neoadjuvant chemotherapy. Scintimammography using 740 MBq Tc-99m sestamibi was performed before, during and after chemotherapy, and sestamibi uptake was scored visually and semiquantitatively to evaluate tumor response. RESULTS In the case of complete response (n = 3) sestamibi uptake decreased 8 days after beginning neoadjuvant chemotherapy and normalized in the following course. Focal uptake decreased more slowly in patients with partial response (n = 3), who showed clear, persisting tracer accumulation after therapy. The patients without response (n = 3) showed a persisting high tumor activity even after chemotherapy was completed. CONCLUSIONS The preliminary data suggest that in contrast to other imaging modalities scintimammography appears to yield early information regarding tumor response to neoadjuvant chemotherapy.