Assessment of primary and metastatic ovarian cancer by positron emission tomography (PET) using 2-[18F]deoxyglucose (2-[18F]FDG).

The potential of positron emission tomography (PET) to distinguish benign from malignant ovarian tissue was evaluated by comparing the results of F-18 fluoro-2-D-deoxyglucose (F-18-FDG) PET scans with computed tomography and surgical findings. If sufficiently sensitive, this method might play a role in localizing metabolically active tumor sites for diagnosis, staging, and follow-up of ovarian cancer. Fifty-one patients had imaging studies prior to laparotomy for suspected ovarian cancer. PET scans were done with an ECAT 931-08-12 or ECAT EXACT (Model 921, Siemens/CTI, Knoxville, TN) after iv injection of 185-370 MBq of F-18-FDG. (ECAT is a trade name for "emission computerized axial tomograph.") Data were acquired in dynamic scanning mode and time activity curves (TACs) were evaluated in multiple regions of interest identified by visual interpretation of the PET scans. Scan interpretation, standardized uptake values, and TAC profiles were related to surgical and histological findings. The results of this pilot study show good correlation between PET and histological findings. The positive predictive value of PET for ovarian cancer was 86% and, perhaps more important, the negative predictive value was 76%. This early work indicates that PET may be useful in the management of patients with ovarian neoplasms by identifying occult foci of metabolically active tumor that do not appear on morphological studies.