Comparison of Ga-68-FAPI-04 and fluorine-18-fluorodeoxyglucose PET/computed tomography in the detection of ovarian malignancies

BackgroundCurrently, fluorine-18-fluorodeoxyglucose (F-18-FDG) is the most frequently used diagnostical radiotracer for PET/computed tomography (PET/CT) in ovarian malignancies. However, F-18-FDG has some limitations. The fibroblast activation protein inhibitor (FAPI) previously demonstrated highly promising results in studies on various tumor entities and Ga-68-labeled FAPI presents a promising alternative to F-18-FDG. This study aimed to compare the performance of Ga-68-FAPI and F-18-FDG PET/CT for imaging of ovarian malignancies. MethodsA total of 27 patients were included in this retrospective study conducted at the Affiliated Hospital of Southwest Medical University between June 2020 and February 2022. The F-18-FDG and Ga-68-FAPI uptakes of tumors, lymph nodes, and distant metastases were quantified using the maximum standardized uptake values, and the tumor-to-background ratios were also evaluated and calculated by using the Wilcoxon signed-rank test. ResultsTwenty-one patients with suspected (n = 11) and previously treated ovarian malignancies (n = 10) were in statistical analysis finally. For detecting tumors, Ga-68-FAPI PET/CT was more sensitive than F-18-FDG PET/CT [14 of 14 (100%) vs. 11 of 14 (78%)], lymph node metastases [75 of 75 (100%) vs. 60 of 75 (80%)] and superior to F-18-FDG PET/CT in terms of the peritoneal and pleural metastases [9 of 9 (100%) vs. 5 of 9 (56%)]. For four of the newly diagnosed patients (n = 11), Ga-68-FAPI PET/CT upstaged the clinical stage compared to F-18-FDG PET/CT. Conclusion(68)Ga-FAPI PET/CT has superior potential in the detection of ovarian cancers, especially in peritoneal carcinomatosis. Ga-68-FAPI PET/CT may be a promising supplement for staging and follow-up of ovarian malignancies.