18F-FDG PET-CT in detecting the primary tumor in patients with metastatic cancers of unknown primary origin
10.3321/j.issn:0253-3766.2008.09.014
- VernacularTitle:18F-FDG PET-CT在原发灶不明转移性肿瘤诊断中的应用
- Author:
Man HU
1
;
Ming-Huan LI
;
Li KONG
;
Ning-Bo LIU
;
Guo-Ren YANG
;
Jin-Ming YU
Author Information
1. 山东省肿瘤医院
- Keywords:
PET-CT;
Metastatic carcinoma;
Diagnosis
- From:
Chinese Journal of Oncology
2008;30(9):699-701
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the value of 18F-FDG PET-CT in detecting the primary tumor in patients with metastatic cancers of unknown primary origin. Methods Sixty-seven patients with metastatic cancers of unknown primary origin after extensive conventional diagnostic work-up were enrolled into this study, 18F-FDG PET-CT scans were performed at approximately 60 minutes after the intravenous injection of 7.4 MBq 18F-FDG/kg, then delayed imaging scans was done at approximately 180 minutes for detecting the primary focus. The standardized uptake value (SUV)≥2.5 on standard PET/CT imaging was considered as positive. Ten percent increase of retention index (RI) was also regarded as positive. The correlation between 18F-FDG PET-CT results and histopathological and clinical findings were analyzed, and the SUV of detected primary focus and that of metastatic cancers were compared. Results Of the 67 patients, the primary tumors were identified in 39 (53.7%) by 18F-FDG PET-CT, and 36 of them were confirmed by pathology or follow-up. Thirteen distant metastases and seventeen lymphatic metastases were newly discovered by whole body 18F-FDG PET-CT imaging. The SUV of metastatic tumors was significantly lower than that of primary tumors (t=3.470, P=0.001) and closely correlated with that of the primary tumors (r=0.738, P=0.000). Conclusion 18F-FDG PET-CT is not only valuable in identifying the unknown primary tumor in patients with metastatic carcinoma, but can also be used to reveal the biological characteristics of the tumors by functional imaging.
