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 and 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.