RT Journal Article SR Electronic T1 Potential of Dual-Time-Point Imaging to Improve Breast Cancer Diagnosis with 18F-FDG PET JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1819 OP 1824 VO 46 IS 11 A1 Kumar, Rakesh A1 Loving, Vilert A. A1 Chauhan, Anil A1 Zhuang, Hongming A1 Mitchell, Schnall A1 Alavi, Abass YR 2005 UL http://jnm.snmjournals.org/content/46/11/1819.abstract AB The purpose of this study was to assess the utility of dual-time-point imaging for identifying malignant lesions in the breast by 18F-FDG PET. Methods: Fifty-four breast cancer patients with 57 breast lesions underwent 2 sequential PET scans (dual-time-point imaging). The average percent change in standardized uptake values (SUVs) between time point 1 and time point 2 was calculated. All PET study results were correlated with follow-up surgical pathology results. Results: Of the 57 breast lesions, 39 were invasive carcinoma and 18 were postbiopsy inflammation. Among the invasive carcinoma lesions, 33 (85%) showed an increase and 6 (15%) showed either no change or a decrease in SUVs over time. The percent change in SUVs from time point 1 to time point 2 (mean ± SD) was +12.6% ± 11.4% (P = 0.003). Of the 18 inflammatory lesions, 3 (17%) showed an increase and 15 (83%) showed either no change or a decrease in SUVs. The percent change in SUVs from time point 1 to time point 2 (mean ± SD) was −10.2% ± 16.5% (P = 0.03). Of the 57 normal contralateral breasts, 2 (3.5%) showed an increase and 55 (96.5%) showed either no change or a decrease in SUVs. The percent change in SUVs from time point 1 to time point 2 (mean ± SD) was −15.8% ± 17% (P = 0.005). Conclusion: There is increasing uptake of 18F-FDG over time in breast malignancies, whereas the uptake of 18F-FDG in inflammatory lesions and normal breast tissues decreases over time. A percent change of +3.75 or more in SUVs over time is highly sensitive and specific in differentiating inflammatory lesions from malignant lesions.