Imaging of proliferation in breast cancer with 18F-FDG PET: Correlation between partial volume corrected SUV and MiB-1 proliferation index

Objectives: To assess the role of 18F-FDG quantification with Partial Volume Correction (PVC) as potential marker for MiB-1 proliferation index in breast cancer. Methods: An integrated protocol was developed involving 43 oncological patients with breast cancer. All patients underwent a 18F-FDG PET-CT study before surgery. Patient weight, injected dose and residual were measured. Averaged Body-Weight Standardized Uptake Value with correction for Partial Volume Effect (PVC-SUVBW) was calculated. After surgery, excised tissues were sectioned and classified according to the WHO guidelines, evaluating MiB-1 index. A cut-off of 18% for MiB-1 proliferation index allowed to divide the patients in two groups. Mann-Whitney test was used to evaluate the differences between the two groups with respect to the PVC-SUVBW. Univariate linear regression was also applied. Results: SUV strongly correlated with MiB-1 proliferation index (p < 0.001), in particular PVC-SUV =9.19±6.28 g/cc for tumor with an expression of MiB-1 18%, while PVC-SUV = 4.00 ± 2.29 for tumor with an expression of MiB-1<18%. Linear univariate regression confirmed that the relationship between MiB-1 proliferation index and in vivo SUV biomarker. Conclusions: A strong correlation between SUV and MiB-1 proliferation index was found, suggesting that SUV can be evaluated as a surrogate of marker of proliferation