RT Journal Article SR Electronic T1 Tissue-Specific Effects on Uptake of 99mTc-Sestamibi by Breast Lesions: A Targeted Analysis of False Scintigraphic Diagnoses JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1822 OP 1828 VO 45 IS 11 A1 Reinhold Tiling A1 Katrin Stephan A1 Harald Sommer A1 Naim Shabani A1 Rainer Linke A1 Klaus Hahn YR 2004 UL http://jnm.snmjournals.org/content/45/11/1822.abstract AB The limited spatial resolution of γ-cameras is commonly considered the main reason for the low sensitivity of scintimammography in the detection of small carcinomas. The present study assessed whether uptake of 99mTc-sestambi is affected by certain tissue-specific parameters besides the size of the tumor. Methods: Surgical specimens from 75 patients (30 benign lesions, 8 of which had shown false-positive scintigraphic findings, and 45 carcinomas, 8 of which had shown false-negative scintigraphic findings) were subjected to a distinct histopathologic/immunohistochemical reevaluation. Tissue-specific parameters (lesion size, cellular density, vascularity, signs of inflammation, proliferative activity, multidrug resistance expression, and receptor status) were visually scored and correlated with the sestamibi uptake on scintimammograms. Results: A clear relationship was found between sestamibi uptake and tumor size. As previously assumed, a lesion size of less than 1 cm in diameter was found to be one reason for false-negative scintigraphic diagnoses. In addition, a low cell count, low vascularity, and absence of inflammation in carcinomas had a negative effect on uptake of the radiopharmaceutical. The decisive factor for increased tracer uptake by benign lesions was the presence of inflammatory changes. No correlation could be found between sestamibi uptake and proliferative cellular activity, multidrug resistance expression, or the receptor status of the tumor. Conclusion: Because all mentioned findings were statistically significant only in part, it is to be supposed that uptake of 99mTc-sestambi by breast lesions is determined by various tissue parameters in interaction.