Fusion imaging in the preoperative assessment of the extension of disease in patients with advanced ovarian cancer: feasibility and agreement with laparoscopic findings

Objectives: Fusion imaging is an emerging technique that can fuse real time ultrasound examination with other imaging modalities such as computed tomography (CT), magnetic resonance, and positron emission tomography. The primary aim of the study was to evaluate the Fusion imaging feasibility in patients with advanced ovarian cancer. The secondary aims were: 1) to compare agreement laparoscopic findings with Fusion, CT scan alone and ultrasound alone in assessing the extension of intra-abdominal disease; 2) to evaluate the time required by the Fusion technique. Methods: patients with clinical and/or radiographic suspicion of advanced ovarian or peritoneal cancer and candidate to surgery were prospectively enrolled between December 2019 and September 2020. All patients underwent CT scan, ultrasound and Fusion examination in order to evaluate the presence/absence of the following abdominal cancer features according to the laparoscopy-based scoring model (PIV: Predictive Index Value): supracolic omentum disease, visceral carcinomatosis on the liver, lesser omental carcinomatosis and/or visceral carcinomatosis on the lesser curvature of stomach and/or on the spleen, parietal peritoneal involvement of paracolic gutter/-s and/or anterior abdominal wall, parietal peritoneal involvement of diaphragm and visceral carcinomatosis on small and large bowel (except rectosigmoid). Feasibility of the Fusion examination was evaluated. Agreement between each imaging method (ultrasound, CT scan and Fusion) and laparoscopy (considered as reference standard) was calculated using Cohen's kappa coefficient. Results: 52 patients were enrolled in the study. Fusion examination was feasible in 51/52 (98%) patients (in one patient the CD was not working). Two other patients were excluded because laparoscopy was not performed. 49 women were considered for final analysis. Kappa values between CT, ultrasound, Fusion and laparoscopy in assessing the PIV parameters were respectively: 0.781, 0.845 and 0.896 for great omentum; 0.329, 0.608 and 0.847 for liver surface, 0.472, 0.549 and 0.756 for lesser omentum and/or stomach and/or spleen; 0.385, 0.588 and 0.795 for parietal peritoneum; 0.385, 0.497 and 0.657 for diaphragm; 0.336, 0.410 and 0.469 for bowel. The median time needed to perform Fusion examination was 20 (range 10-40) minutes. Conclusions: Fusion of CT and ultrasound images is feasible in patients with advanced ovarian cancer and improves the agreement with the surgical findings when compared with the single imaging methods (ultrasound or CT scan). This article is protected by copyright. All rights reserved.