Efficacy of Ca-125 exchange rate and ¹⁸F-FDG Pet/Ct in predicting progression in ovarian cancer

EANM 2025, 04 Ekim 2025, ss.573, (Tam Metin Bildiri)

Aim/Introduction: Ovarian cancer is one of the leading causes

of cancer-related deaths among gynecologic malignancies.

Many studies have shown that ¹⁸F-FDG PET/CT provides high

accuracy in recognizing ovarian cancer recurrence. The aim of this

study was to investigate the relationship between progression

in CA-125 marker and ¹⁸F-FDG PET/CT and to compare the

diagnostic accuracy of these two methods and to evaluate their

contribution in progression follow-up. Materials and Methods:

In this retrospective study, a total of 330 patients with serous

ovarian cancer who were admitted to the Nuclear Medicine

Clinic between January 2013 and January 2018 were analyzed.

The study included 23 patients who underwent 18F-FDGPET/CT

imaging for suspected recurrence and for whom CA-125 marker

data were available. Each patients CA-125 value at the time of

imaging and CA-125 values approximately one month ago were

recorded. In addition, ¹⁸F-FDG PET/CT images were re-evaluated

for progression. In the study, CA-125 change rate was calculated

and its relationship with progression was evaluated and the

predictive power of CA-125 change rate was determined by

statistical analysis. Results: All patients included in the study were

diagnosed with serous ovarian carcinoma. All patients underwent

¹⁸F-FDG PET/CT imaging with suspicion of recurrence due to

elevatedCA-125 marker. The mean age of the patients was 55±12

years (32-80). In the study, CA-125change rate was calculated and

its relationship with progression was evaluated. Then, Receiver

Operating Characteristic (ROC) analysis was performed to evaluate

the predictive power ofCA-125 change rate. As a result of the ROC

analysis, the area under the curve (AUC) of CA-125 change rate

was calculated as 0.826 with a standard error of 0.077 and p=0.070.

The confidence interval was 0.676-0.976. The optimal cut-off value