A prospective comparison of integrated FDG-PET/contrast-enhanced CT and contrast-enhanced CT for pretreatment imaging of advanced epithelial ovarian cancer.

OBJECTIVE

The use of tumor debulking surgery in the management of epithelial ovarian cancer (EOC), which is often disseminated in the peritoneal cavity at the time of diagnosis, has a significant impact on prognosis. We compared (18)F-fluorodeoxyglucose (FDG) positron emission tomography/contrast-enhanced computed tomography (PET/CT) to contrast-enhanced CT for the detection of dissemination into the abdominal cavity preventing successful primary debulking surgery.

METHODS

Forty-one women with EOC underwent preoperative whole-body low-dose FDG-PET/CT followed by diagnostic high dose contrast-enhanced CT scan, and the results were compared with systematically recorded surgical findings as a reference standard. Both site-based and patient-based analyses were conducted.

RESULTS

FDG-PET/CT was superior to conventional CT for the detection of carcinomatosis in subdiaphragmatic peritoneal surfaces (p=0.020) and in the bowel mesentery (p=0.001). Patient-based analysis of upper abdominal areas requiring extensive surgical procedures showed no significant differences between the two imaging methods. The sensitivity of PET/CT and CT was poor in certain areas of the peritoneal cavity (64% vs. 27% in the small bowel mesentery and 65% vs. 55% in the right upper abdomen). Extra-abdominal disease spread was detected by PET/CT in 32 patients and by CT in 25 patients.

CONCLUSIONS

PET/CT was not superior to CT for the detection of intra-abdominal disease spread. Patients with suspected EOC should be referred for upfront radical surgery regardless of the results of preoperative imaging studies. PET/CT is more effective for the detection of extra-abdominal disease than CT, but the clinical significance of this finding is unclear.