Standardized uptake value variations of normal glandular breast tissue at dual time point FDG-PET/CT imaging

Purpose: To study the relationship between (FDG) uptake expressed quantitatively as standardized uptake values (SUVs) in normal breast tissues and breast density, age, menopausal status determined during dual-time point FDGPET/CT imaging. Materials and Methods: maximum and average SUVs were determined in two hundred eighty four patients (all females; mean age 55.5 ± 14.1 range 13-84 years, 115 premenopausal, 169 postmenopausal) with newly diagnosed unilateral breast cancer, gynecological cancer and lung cancer were analyzed. One hundred forty two (50%) patients had dense breast whereas 142 (50%) patients had non-dense breast according to the ACR Lexicon criteria. All the patients underwent dual time point imaging sequential PET/CT scans for preoperative staging. In the present study, we analyzed maximum and average SUVs for the normal breast parenchyma and nipple regions. Results: Of the 284 normal breast parenchyma; 64.4% showed a decrease and 35.6% showed either no change 20.1% or an increase 15.5% in SUV over time. Similar values for the normal tissue in the nipple region were; 77.5% showed a decrease and 22.5% showed either no change 13% or an increase 9.5% in SUV over time. There was significant difference in maximum and average SUVs of breast parenchyma and nipple in patients with dense and nondense breasts (p < 0.0001). There were trends of negative relationship between physiological FDG uptake and age (p < 0.0001). Furthermore, there was significant difference in maximum and average SUVs of breast parenchyma with different menopausal status (p < 0.0001). Our analysis revealed that breast density, age and menopausal status were significant predictors for FDG uptake in the normal breasts. Conclusion: There was a significant difference in SUVs between the dense and non-dense normal breast. Menopausal status and age do significantly affect the uptake of FDG. Delayed phase imaging can improve the accuracy of the test in the evaluation of breast cancer as the physiological FDG uptake decrease so the pathological uptake becomes prominent and could be easily depicted.