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).


CONCLUSION
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.


KEY POINTS
• 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.
['Nakajo|Masatoyo|M|', 'Jinguji|Megumi|M|', 'Fukukura|Yoshihiko|Y|', 'Kajiya|Yoriko|Y|', 'Tani|Atushi|A|', 'Nakajo|Masayuki|M|', 'Nakabeppu|Yoshiaki|Y|', 'Arimura|Hiroshi|H|', 'Nishio|Yoshihiko|Y|', 'Nakamura|Fumihiko|F|', 'Yoshiura|Takashi|T|']
D000310:Adrenal Gland Neoplasms D000328:Adult D000368:Aged D000369:Aged, 80 and over D003937:Diagnosis, Differential D005260:Female D019788:Fluorodeoxyglucose F18 D006801:Humans D008055:Lipids D008297:Male D008875:Middle Aged D049268:Positron-Emission Tomography D012372:ROC Curve D014057:Tomography, X-Ray Computed
Adrenal Adrenal tumour FDG FLT PET/CT