FDG-PET/CT and FLT-PET/CT for differentiating between lipid-poor benign and malignant adrenal tumours.
OBJECTIVE
To compare F-18-fluorodeoxyglucose (FDG) and F-18-fluorothymidine (FLT) PET/CT examinations for differentiating between benign and malignant adrenal tumours.


METHODS
Thirty lipid-poor benign and 11 malignant tumours of 40 patients were included. FDG- and FLT-based indices including visual score, maximum standardized uptake value (SUVmax) and FDG adrenal lesion/liver SUVmax (A/L SUVmax) or FLT adrenal lesion/back muscle SUVmax (A/B SUVmax) ratio were compared between benign and malignant tumours using the Mann-Whitney's U or Wilcoxon signed-rank test, and their diagnostic performances were evaluated by means of the area under the curve (AUC) values derived from the receiver operating characteristic analysis.


RESULTS
All indices were significantly higher in malignant than benign tumours on both images (p < 0.05 each). On FDG-PET/CT, the sensitivity, specificity, and accuracy were 91 %, 63 % and 71 % for visual score, 91 %, 67 % and 73 % for SUVmax, and 100 %, 70 % and 78 % for A/L SUVmax ratio, respectively. On FLT-PET/CT, they were 100 %, 97 % and 98 % for visual score, SUVmax and A/B SUVmax ratio, respectively. All FLT indices were significantly higher than those of FDG in AUC (p < 0.05 each).


CONCLUSIONS
FLT-PET/CT may be superior to FDG-PET/CT in differentiating lipid-poor benign from malignant adrenal tumours because of higher specificity and accuracy.


CONCLUSIONS
• All FDG indices were significantly higher in malignant than in benign tumours. • All FLT indices were significantly higher in malignant than in benign tumours. • All FLT indices were significantly higher than those of FDG in AUC.
Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan. toyo.nakajo@dolphin.ocn.ne.jp.
Masatoyo
M
Nakajo
Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Megumi
M
Jinguji
Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Yoshihiko
Y
Fukukura
Department of Radiology, Nanpuh Hospital, 14-3 Nagata, Kagoshima, 892-8512, Japan.
Yoriko
Y
Kajiya
Department of Radiology, Nanpuh Hospital, 14-3 Nagata, Kagoshima, 892-8512, Japan.
Atushi
A
Tani
Department of Radiology, Nanpuh Hospital, 14-3 Nagata, Kagoshima, 892-8512, Japan.
Masayuki
M
Nakajo
Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Yoshiaki
Y
Nakabeppu
Department of Diabetes and Endocrine Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Hiroshi
H
Arimura
Department of Diabetes and Endocrine Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Yoshihiko
Y
Nishio
Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Fumihiko
F
Nakamura
Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
Takashi
T
Yoshiura
D000310:Adrenal Gland Neoplasms / Q000737:chemistry / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008055:Lipids / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D012372:ROC Curve; D014057:Tomography, X-Ray Computed / Q000379:methods*
D008055:Lipids; D019788:Fluorodeoxyglucose F18
Adrenal; Adrenal tumour; FDG; FLT; PET/CT