[en] Full text: In the post-operative surveillance of ovarian carcinoma patients, the CA-125 levels play an important role. However there is no direct relationship between the level of CA-125 and the metastatic volume. Hence FDG-PET scan would play a major role in the detection and quantification of the metastatic disease burden. We present our retrospective analysis of 30 ovarian carcinoma patients in this context. Totally 30 patient were included in the study. All patients had CA-125 estimation as part of regular follow up after initial surgery. All those patients who had elevated CA-125 levels were further investigated with either CT/MRI/USG initially followed by PET-CT scan in those patients where focal disease was detected by one of the 3 anatomical modalities. For purpose of analysis patients were grouped into 3 categories based on CA-125 levels: Group A: CA-125 - 0 to 35 IU/ml (n=10), Group B: CA-125 35 to 70 IU/ml (n=6), Group C: CA-125->70 IU/ml (n=14). The volume of disease detected on PET/CT scan was correlated with CA-125 levels and also its impact on treatment approach was analysed. In Group A - 3 patients had no disease (no treatment given), 6 had distant metastasis (chemotherapy) and 1 had localized disease (surgical excision). Group B - 2 patients had localized disease (surgery + chemotherapy in one patient) and 4 had distant metastasis (chemotherapy). Group C - 13 patients had distant metastasis including lungs (2 patients) and bones (4 patients) (chemotherapy + radiotherapy), and 1 patient had localized disease (surgical removal). Out of 30 patients, there were 8 patients (26.6%) who showed solitary lesions on CT scan, however in 3 of these 8 patients PET/CT scans showed multiple sites resulting in 37.5% upstaging and thereby change of therapy in the form of surgery to systemic chemotherapy. From our analysis we conclude that the CA-125 levels correlated well with volume of metastatic disease on PET/CT in higher range (CA-125: >70 IU/ml) while in the lower range (CA-125: 0-35 IU/ml) the same correlation was not observed. Hence PET/CT would be superior to CA-125 in accurate assessment of metastatic burden. We also conclude that PET/CT upstages the disease and thereby alters the therapeutic approach in 38% of patients