Preoperative assessment of asymptomatic adnexal masses by positron emission tomography and F-18-fluorodeoxyglucose

Aim: To evaluate use of F-18-FDG-PET in assessment of dignity of asymptomat ic adnexal masses. Methods: 85 asymptomatic patients with suspicious, asymp tomatic adnexal masses were evaluated. Static FDG-PET (Exact HR+ or ECAT 93 1) imaging of the abdomen was performed following application of 222-555 MB q F-18-FDG. iterative reconstruction was applied. PET data were analysed vi sually, at first without and second together with MRT images. Final diagnos is was made by histopathology. Results: FDG-PET allowed correct identificat ion of 4 of 8 malignant adnexal rumors. False negative results were obtaine d in 2 adenocarcinomas stage pT1a and 2 borderline-tumors. In 60 out of 77 benign adnexal masses malignancy could be excluded. False positive FDG-upta ke, partly because of misinterpretation of gastrointestinal activity, was f ound in 3 inflammatory processes, 1 teratoma, 1 benign schwannoma, 1 dermoi d cyst, 1 benign thecoma, 1 serous cyst, 1 serous cystadenoma, 2 mucinous c ystadenomas, 2 corpus luteum cysts, 3 endometriosic cysts and 1 sactosalpin x. The overall sensitivity and specifity of FDG-PET alone were 50% and 78%. Evaluation together with MRT images showed a sensitivity of 50% and a spec ifity of 86%. Conclusion: Sensitivity of FDG-PET in detection of borderline -tumors and early stage ovarian cancer seems to be limited. Low incidence o f malignant ovarian tumors requires for assesment of dignity a procedure of high specifity, that is not reached by FDG-PET neither without nor togethe r with MRT images for topographic orientation. Therefore use of FDG-PET for assesment of dignity in suspicious, asymptomatic ovarian tumors is limited .