Validation of therapeutic response assessment by bone scintigraphy in patients with bone-only metastatic breast cancers during zoledronic acid treatment: comparison with computed tomography assessment

摘要

Purpose: To validate the use of bone scintigraphy (BS) versus computed tomography (CT) for therapeutic monitoring in patients during treatment with zoledronic acid. Materials and Methods: Eleven patients with bone-only metastatic disease and being treated with zoledronic acid were included. The effects of therapies including chemotherapy and hormone therapy were evaluated in 25 separate examinations in total as follows: complete response (CR), when no bone metastasis was visible; partial response (PR), when a decrease in the lesion area was detected; stable disease (SD), when no or slight change was observed; and progressive disease (PD), when new or enlarged lesion areas were observed. Results: The accuracies of examination by Readers 1, 2, and 3 respectively were 76%, 80% and 76% for BS, 52%, 48%, and 40% for CT, and 64%, 52% and 60% for BS and CT combined with Readers 2 and 3 observing significant differences between CT and BS results. The rates of interobserver agreement between Readers 1 and 2, between Readers 1 and 3, and between Reader 2 and 3 respectively, were 84%, 80% and 88% (κ = 0.648, 0.561 and 0.766) for BS, 52%, 56%, and 60% (κ = 0.180, 0.278 and 0.282) for CT, and 52%, 60%, and 56% (κ = 0.215, 0.282 and 0.232) for CT and BS combined. Conclusion: BS is effective for assessing the response of bone metastasis to therapy in patients during zoledronic acid treatment.