Detection of hepatic metastases using dual-time-point FDG PET/CT scans in patients with colorectal cancer.
OBJECTIVE
The purpose of this study was to determine the most useful parameter of dual-time-point 2-deoxy-2-[¹⁸F]fluoro-D: -glucose positron emission tomography/computed tomography (PET/CT) for detection of hepatic metastases in patients with colorectal cancer.


METHODS
Thirty-nine patients had undergone a dual-time-point PET/CT scan and a subsequent histopathological confirmation for a workup of hepatic metastases. Detection rates were compared for visual analysis score, standardized uptake value (SUV), tumor-to-liver uptake ratio (TLR), and percent changes of the SUV and TLR.


RESULTS
Of 91 liver lesions, 86 lesions were confirmed as metastases. The SUV and TLR of metastatic lesions on the delayed images were higher than those on the first scan (p < 0.001). The signal-to-noise ratio of the delayed PET scan was higher than that of the first scan (p < 0.0001). The TLR and SUV of the delayed scan showed the highest detection rates of 92% and 88%, whereas percent changes of SUV and TLR showed the lowest detection rates (51%, 67%). Visual analysis detected 87% on the delayed scan and 77% on the first scan.


CONCLUSIONS
A delayed scan is more favorable for the detection of hepatic metastases of colorectal cancer, and the TLR on the delayed scan was the most useful parameter.
Lee
Jeong Won
JW
Department of Nuclear Medicine, Jeju National University Hospital, Jeju, Jeju Special Self-Governing Province, South Korea.
Kim
Seok-Ki
SK
Department of Nuclear Medicine, National Cancer Center Research Institute and Hospital, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do, 410-769, South Korea. skkim@ncc.re.kr.
Lee
Sang Mi
SM
Department of Nuclear Medicine, National Cancer Center Research Institute and Hospital, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do, 410-769, South Korea.
Moon
Seung Hwan
SH
Department of Nuclear Medicine, National Cancer Center Research Institute and Hospital, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do, 410-769, South Korea.
Kim
Tae-Sung
TS
Department of Nuclear Medicine, National Cancer Center Research Institute and Hospital, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do, 410-769, South Korea.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012372:ROC Curve; D013997:Time Factors; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D019788:Fluorodeoxyglucose F18