Improved detection of second primary cancer using integrated [18F] fluorodeoxyglucose positron emission tomography and computed tomography for initial tumor staging.
OBJECTIVE
This study evaluated prospectively the value of integrated whole-body positron emission tomography and computed tomography (PET/CT) using [18F] fluorodeoxyglucose (FDG) in detecting a second primary cancer at the time of the initial staging in comparison with a conventional staging work-up (CSW).


METHODS
The participants were 547 patients diagnosed with cancer who underwent FDG PET/CT imaging for the initial staging. An additional diagnostic evaluation was performed when there were abnormal findings indicative of a second primary cancer on either PET/CT or CSW considering the site and the biologic behavior of the alleged primary tumor.


RESULTS
A total of 27 second primary malignant tumors were identified in 26 of the 547 patients (4.8%). FDG PET/CT found 45 lesions indicative of a second primary cancer, of which 24 lesions were proved to be a second primary cancer, seven were clinically unexpected metastases, and 14 lesions were benign. Therefore, sensitivity and positive predictive value of FDG PET/CT in detecting a second primary cancer or an unexpected metastasis were 91% (31 of 34) and 69% (31 of 45), respectively. In contrast, CSW could not identify 16 second primary cancers and one metastatic lesion.


CONCLUSIONS
FDG PET/CT at the time of the initial staging is useful for screening a second primary cancer with a high sensitivity. An additional diagnostic work-up is essential when abnormal findings, which are indicative of a second primary cancer, are obtained on PET/CT images to rule out the presence of either a second primary cancer or an unexpected metastasis.
Choi
Joon Young
JY
Department of Nuclear Medicine, Samsung Medical Center, 50 Ilwon-dong, Kangnam-ku 135-710 Seoul Republic of Korea.
Lee
Kyung Soo
KS
Kwon
O Jung
OJ
Shim
Young Mog
YM
Baek
Chung-Hwan
CH
Park
Keunchil
K
Lee
Kyung-Han
KH
Kim
Byung-Tae
BT
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009369:Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D016609:Neoplasms, Second Primary / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18