RT Journal Article SR Electronic T1 Factors Influencing the Uptake of 99mTc-Sestamibi in Breast Tissue on Molecular Breast Imaging JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 13 OP 20 DO 10.2967/jnmt.114.150128 VO 43 IS 1 A1 O’Connor, Michael K. A1 Hruska, Carrie B. A1 Tran, Thuy D. A1 Swanson, Tiffinee A1 Conners, Amy Lynn A1 Jones, Katie A1 Rhodes, Deborah J. YR 2015 UL http://tech.snmjournals.org/content/43/1/13.abstract AB The purpose of this study was to evaluate the impact of changes to a patient’s prandial status, metabolic status (rest vs. exercise), and peripheral blood flow (via caffeine or warming) on the uptake of 99mTc-sestamibi in breast tissue. Methods: A total of 154 subjects participated in 1 of 4 study groups that evaluated the effects of 4 types of intervention on the uptake of 99mTc-sestamibi in breast tissue (effect of fasting, light exercise, caffeine, and peripheral warming). Molecular breast imaging was performed before and after each intervention. Count density was assessed in counts/cm2/MBq from the mediolateral oblique view in all studies. Results: Uptake of 99mTc-sestamibi in breast tissue increased by approximately 25% from 6.6 counts/cm2/MBq in the fed state to 8.3 counts/cm2/MBq with fasting. Peripheral warming also resulted in an approximately 20% increase in count density from 9.1 to 10.9 counts/cm2/MBq. Conversely, exercise caused a 35% drop in count density relative to the resting state. Uptake did not seem to be influenced by caffeine and did not correlate with a patient’s height, weight, or breast thickness. There was only a weak correlation between breast activity and body surface area. Conclusion: The combined effects of fasting and warming resulted in an approximately 50% increased uptake of 99mTc-sestamibi in breast tissue relative to that observed in a reference group to whom no preparatory instructions had been given. Optimal patient preparation before administration of 99mTc-sestamibi should permit a corresponding reduction in either acquisition time or required dose of 99mTc-sestamibi.