Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the detection of recurrence and peritoneal metastasis from ovarian cancer in correlation with cancer antigen-125 tumor marker levels

Abstract

Background: The chronic nature of ovarian cancer and disease recurrence has a considerable impact on the assessment of follow-up strategies and treatment planning for both oncologists and radiologists. It is imperative to conduct adequate follow-up in ovarian cancer to detect and treat recurrence as early as possible. Presently, surveillance of patients with this malignancy involves the combination of serial CA-125 assay and diverse imaging procedures, yet normal CA-125 levels cannot entirely rule out disease relapse. PET/CT provides whole-body functional imaging that does not necessities contrast injection, and allows for precise diagnosis and restaging of patients with suspected ovarian cancer recurrence, thereby strongly impacting disease management decisions. Our study aims to evaluate the value of FDG-PET/CT as a follow-up imaging tool in detecting and localizing recurrence of ovarian cancer, in conjunction with CA-125 tumor markers. Results: In our study, it was demonstrated that recurrent disease manifested in FDG-PET/CT in 24 cases, with 9 of those cases exhibiting CA-125 levels within the normal range. There were two instances of false negative results and one instance of false positive results in FDG-PET/CT. Additionally, three cases were found to be free of disease relapse in FDG-PET/CT and exhibited normal CA-125 levels throughout the follow-up period (true negative). The prevalence of disease recurrent sites was 12% for local recurrence, 60% for peritoneal metastasis, 64% for nodal deposits and 28% for distant metastatic disease. The accuracy of FDG-PET/CT was 88.8%, with a sensitivity of 91.3% and specificity of 75%. Furthermore, FDG-PET/CT showed a positive predictive value of 95.5% and a negative predictive value of 60.3%. Conclusions: PET/CT imaging provides a comprehensive and functional view of the entire body, which can accurately diagnose and restage cases with ovarian cancer recurrence. This approach plays a critical role in identifying peritoneal carcinomatosis and is considered a more dependable method than CA-125 tumor markers for detecting and monitoring ovarian cancer recurrence. Additionally, PET/CT imaging has the potential to decrease the number of second-look laparotomies and can thus significantly impact the management plan.