Diagnosis of complex renal cystic masses and solid renal lesions using PET imaging: comparison of 11C-acetate and 18F-FDG PET imaging.
OBJECTIVE
The study aims to assess the usefulness of PET with C-acetate and F-FDG to differentiate renal cell carcinoma (RCC) from complicated renal cysts.


METHODS
Thirty-one patients were enrolled, 14 patients with complicated renal cysts (12 with Bosniak III and 2 with Bosniak IV) and 17 patients with 19 solid renal tumors. The patients underwent both C-acetate PET and FDG PET. Nephrectomy or partial nephrectomy was performed after the PET scans.


RESULTS
In 29 patients, 32 renal lesions were diagnosed as RCC. Twenty-three of the 32 RCCs (72%) had positive C-acetate PET findings, whereas only 7 FDG PET studies were positive (22%). Considering the relationship between tumor size measured by macroscopic appearance of resected tumors and PET results, 22 of 25 (88%) tumors more than 1.5 cm showed positive C-acetate PET findings. In 12 patients with Bosniak III renal cysts, 10 renal lesions were diagnosed as RCC. In this subgroup, 5 of the 10 RCCs (50%) had positive C-acetate PET findings, whereas 2 RCCs (20%) had positive FDG PET findings. None of the cases with benign findings had positive C-acetate PET or FDG PET scans.


CONCLUSIONS
C-acetate PET demonstrates a pronounced increase in tracer uptake in RCC, especially in renal tumors more than 1.5 cm, and displays a higher sensitivity than FDG PET. These preliminary data show that C-acetate may be a useful PET tracer to exclude RCC in complex renal cysts.
From the *Department of Urology, Faculty of Medical Sciences, and †Biomedical Imaging Research Center, University of Fukui, Fukui; ‡Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki; §Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa, Chiba; and ¶Department of Urology, Fukui Red Cross Hospital, Fukui, Japan.
Nobuyuki
N
Oyama
Hideaki
H
Ito
Noriko
N
Takahara
Yoshiji
Y
Miwa
Hironobu
H
Akino
Takashi
T
Kudo
Hidehiko
H
Okazawa
Yasuhisa
Y
Fujibayashi
Kazuto
K
Komatsu
Kenji
K
Tsukahara
Osamu
O
Yokoyama
D000085:Acetates; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D049268:Positron-Emission Tomography; D047368:Tumor Burden
D000085:Acetates; C438206:carbon-11 acetate; D019788:Fluorodeoxyglucose F18; D002244:Carbon