Standardized uptake values of uterine leiomyoma with 18F-FDG PET/CT: variation with age, size, degeneration, and contrast enhancement on MRI.
OBJECTIVE
To assess the effect of age, size, the degree of degeneration, and contrast enhancement on magnetic resonance imaging (MRI) on 18F-fluoro-2-deoxyglucose (18F-FDG) uptake in uterine leiomyomas using quantitative standardized uptake values (SUVs).


METHODS
A total of 61 leiomyomas of 41 patients, who underwent combined positron emission tomography/computed tomography (PET/CT) using 18F-FDG and contrast-enhanced MRI were included in this study. Sixty-one leiomyomas were divided into two groups: "non-degenerated" leiomyomas showing distinct low signal intensity on T2-weighted images and intermediate signal intensity on T1-weighted images, and "degenerated" leiomyomas showing other types of signal intensity. Sixty-one leiomyomas were also divided into two groups of "strongly enhancing" leiomyomas and "weakly enhancing" leiomyomas in terms of their degree of contrast enhancement on MRI.


RESULTS
The mean values of the maximum and average SUVs for the total of 61 leiomyomas were 2.34 +/- 0.75 (range 1.59-5.15) and 1.74 +/- 0.50 (0.66-3.95), respectively. There was a moderate negative correlation between the maximum and average SUVs and age (r = -0.43 and P = 0.00016, r = -0.31 and P = 0.029, respectively). Although there was a mild positive correlation between maximum SUV and size (r = 0.35 and P = 0.011), there was no significant difference between average SUV and size. Although there was no significant difference in average SUV between "degenerated" and "non-degenerated" leiomyomas, the maximum SUV of "degenerated" leiomyomas was significantly higher than that of "non-degenerated" leiomyomas (P = 0.0012). The degree of contrast enhancement on MRI was not significantly correlated with 18F-FDG uptake.


CONCLUSIONS
Mild or moderate uptake of 18F-FDG is often observed in uterine leiomyoma and declines with age, and should not be confused with malignant accumulation.
Kitajima
Kazuhiro
K
Department of Radiology, Dokkyo Medical University School of Medicine, 880 Kita-kobayashi, Mibu, Shimotsuga-gun, Tochigi, Japan. kazu10041976@yahoo.co.jp
Murakami
Koji
K
Yamasaki
Erena
E
Kaji
Yasushi
Y
Sugimura
Kazuro
K
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D049628:Body Size; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D007889:Leiomyoma / Q000175:diagnosis* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014594:Uterine Neoplasms / Q000175:diagnosis* / Q000378:metabolism*
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18