Purpose
To estimate the value of FDG-PET in the preoperative diagnosis of uterine endometrial cancer, the primary site and the extra-uterine sites, especially pelvic and para-aortic lymph nodes are evaluated.
Material and methods
From September 2005 to March 2006, 12 patients with uterine endometrial cancer (stage IA - IVB) underwent preoperative FDG-PET. Preoperative diagnosis by FDG-PET imaging and pathological diagnosis of surgical specimens were compared in the following sites: the uterus, adnexa (2 sites), pelvic lymph nodes and para-aortic lymph nodes (11 sites) and other sites.
Results
The uterus; One patient with stage IA disease (2mm) was not detected by FDG-PET (false negative). Adnexa; FDG-PET uptake suggested the right ovarian metastasis in one patient, but pathology revealed primary ovarian cancer (double cancer). Ovarian metastases (left side 1mm in one patient and left side 5mm in one patient) were not detected by FDG-PET (false negative). Pelvic and Para-aortic lymph nodes; When analyzed in the 11 sites mentioned above, FDG-PET had 60% sensitivity, 100% specificity, 100% positive predictive value, 96% negative predictive value, and 96% accuracy. Other sites; Thyroid cancer was detected in one patient.
Conclusion
A high positive predictive value and a specificity of FDG-PET were found in this study. FDG-PET was also useful in detecting co-existing occult cancer, since increased incidence of multiple primary malignancies is reported in patients with uterine endometrial cancer.