Physiological fluctuation of (99m)Tc-sestamibi uptake in normal mammary glands: a systematic investigation in female rats.
BACKGROUND
Scintimammography is an imaging tool for the diagnosis and management of primary breast tumors. There remains a significant knowledge gap regarding the physiological fluctuations in the basal level of (99m)Tc-sestamibi uptake in normal mammary tissues with respect to the female reproductive cycle.


OBJECTIVE
To systematically characterize (99m)Tc-sestamibi uptake in normal mammary tissues in female Sprague Dawley (SD) rats in different estrous phases.


METHODS
The exact phase of the reproductive cycle was determined in 18 female SD rats. Each rat was sacrificed at 20 min after (99m)Tc-sestamibi injection (14.8 MBq/kg). The mammary glands were dissected, and the radioactivity uptake was measured by gamma counting.


RESULTS
Tc-99m-sestamibi uptake oscillates by about twofold and reaches a maximum at the proestrous phase of the rat reproductive cycle.


CONCLUSIONS
Tc-99m-sestamibi uptake fluctuates significantly in normal mammary tissues in synchrony with the female reproductive cycle, and peaks in the proestrous phase in rats, which is equivalent to the early to mid-follicular phase in the human menstrual cycle. This finding will likely benefit the detection of breast lesions that may otherwise be obscured by fluctuating background signals in surrounding normal breast tissues.
Larson
M
M
Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
Larson
M
M
Li
Zhixin
Z
Larson
M
M
Li
Zhixin
Z
Hall
C L
CL
Jensen
E
E
McAllister
D M
DM
Kalyanaraman
B
B
Zhao
Ming
M
D000818:Animals; D030762:Estrous Cycle; D005260:Female; D008321:Mammary Glands, Animal / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D051381:Rats; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics*
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi