Abstract
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Objectives: The purpose of this study was to determine whether dual time point FDG-PET imaging can differentiate between post biopsy inflammation and residual invasive tumor in patients with newly diagnosed breast cancer. Methods: Biopsy proven 161 breast cancer patients underwent two sequential FDG-PET scans (dual time point imaging) for preoperative staging. The mean time interval between the injection of FDG and the first and second scans were approximately 63 minutes and 104 minutes, respectively. The maximum standardized uptake value (SUVmax) of FDG was measured from the region of interest (ROI), which was placed at the site of the lesion on the PET scans from both time points (SUVmax1 and SUVmax2). The percent change in peak SUV between time points 1 and 2 (Δ%SUVmax) was calculated. The SUV measurements and the percent changes in SUVmax over time were correlated with surgical findings in all patients. Results: Surgical pathology revealed residual invasive cancer in 130 and only biopsy related reaction and/or inflammation in 31 patients. The mean ±SD of the SUVmax1, the SUVmax2 and the Δ%SUVmax were 3.5±3.2, 3.9±3.7, and 6.4±13.9% for invasive, 1.7±0.6, 1.7±0.7 and 0.7±13.7% for biopsy related inflammation group, respectively. The differences between these values were statistically significant (p<0.001 for all). Conclusions: The residual invasive cancer group showed significantly higher SUV values and higher rate of increase over time than those of the biopsy related inflammation group. Therefore, these data demonstrate that dual point time PET imaging can differentiate between residual invasive tumors from inflammation after biopsy in patients with breast cancer.
Research Support (if any): This work was supported by a Public Health Services Research Grant from the National Institutes of Health.
- Society of Nuclear Medicine, Inc.