127 Background: To explore the feasibility, accuracy and related influencing factors of spraying γ -GGT fluorescent probe in visual imaging of epithelial ovarian cancer. Methods: This study employed a previously developed spray-type γ-GGT fluorescent probe in fresh ex vivo epithelial ovarian cancer tissues. The experimental group selected ovarian cancer lesions of varying sizes and observed fluorescence imaging after spraying different concentrations of the probe. The optimal imaging concentration and observation time were determined based on pathological results. The validation group then used the optimal parameters to image primary and metastatic lesions, normal tissue, and suspicious areas, confirming the probe's accuracy. Clinical data from patients, such as age and stage, were analyzed to identify factors affecting probe imaging. Results: A total of 16 cases of epithelial ovarian cancer were included in this study, 8 cases were in the experimental group and 8 cases were in the validation group, and the samples were collected from the primary ovarian lesions, omental metastases and peritoneal metastases. In the experimental group, 42 lesions of 3 different diameters were collected. The visible lesions were not found to have any changes in the imaging within 1min-1h after spraying the γ-GGT fluorescent probe, and the SBR value within 1min-1h was between 1.26-1.29, with no statistical difference ( P>0.05), and the visible effect of 5 h was weaker or even invisible to the naked eye, and the best observation time was 1min-1h after spraying the γ-GGT fluorescent probe, and the SBR value of 1min-1h after spraying 10 μM of γ-GGT fluorescent probe was significantly higher than that of 1 μM and 5 μM ( P<0.05), and the best visible effect was achieved by the naked eye, resulting in a minimum effective imaging concentration of 10 μM. A total of 27 points were collected from the lesion with a diameter of <0.3 cm and its surrounding normal tissues with a distance of 1 cm or tissues with a diameter of 1-1.5 cm with a height of suspicion but normal to the naked eye, and 26 of the 27 tissues were confirmed by pathology to be cancerous and 1 was non-cancerous, with a true positive rate of 96.3% and a false positive rate of 3.7%. The overall true positive rate of fluorescence imaging was 98.6%. Univariate analysis showed that there were significant differences in the level of preoperative γ-GGT and the SBR value of preoperative treatment (all P<0.05), and the results of multivariate analysis showed that preoperative treatment was an independent influencing factor for fluorescence imaging of γ-GGT fluorescent probe ( P<0.05). Conclusions: This study tested the γ-GGT fluorescent probe for ovarian cancer imaging, finding 10 μM as the effective concentration and 1 minute to 1 hour as the optimal observation window. The probe's effectiveness is influenced by preoperative treatments.