Blood Flow and Glucose Metabolism in Stage IV Breast Cancer: Heterogeneity of Response During Chemotherapy

OBJECTIVE: The purpose of the study was to compare early changes in blood flow (BF) and glucose metabolism (MR(glu)) in metastatic breast cancer lesions of patients treated with chemotherapy. METHODS: Eleven women with stage IV cancer and lesions in breast, lymph nodes, liver, and bone were scanned before treatment and after the first course of chemotherapy. BF, distribution volume of water (V(d)), MR(glu)/BF ratio, MR(glu) and its corresponding rate constants K(1) and k(3) were compared per tumor lesion before and during therapy. RESULTS: At baseline, mean BF and MR(glu) varied among different tumor lesions, but mean V(d) was comparable in all lesions. After one course of chemotherapy, mean MR(glu) decreased in all lesions. Mean BF decreased in breast and node lesions and increased in bone lesions. V(d) decreased in breast and nodes, but did not change in bone lesions. The MR(glu)/BF ratio decreased in breast and bone lesions and increased in node lesions. In patients with multiple tumor lesions BF and MR(glu) response could be very heterogeneous, even within similar types of metastases. BF and MR(glu) increased in lesions of patients who experienced early disease progression or showed no response during clinical follow-up. CONCLUSION: BF and MR(glu) changes separately give unique information on different aspects of tumor response to chemotherapy. Changes in BF and MR(glu) parameters can be remarkably heterogeneous in patients with multiple lesions.