Thoracic metastasis in advanced ovarian cancer: comparison between computed tomography and video-assisted thoracic surgery

Objective: To determine which computed tomography (CT) imaging features predict pleural malignancy in patients with advanced epithelial ovarian carcinoma (EOC) using video-assisted thoracic surgery (VATS), pathology, and cytology findings as the reference standard. Methods: This retrospective study included 44 patients with International Federation of Obstetrics and Gynecology (FIGO) stage III or IV primary or recurrent EOC who had chest CT days before VATS. Two radiologists independently reviewed the CT studies and recorded the presence and size of pleural effusions and of ascites; pleural nodules, thickening, enhancement, subdiaphragmatic tumour deposits and supradiaphragmatic, mediastinal, hilar, and retroperitoneal adenopathy; and peritoneal seeding. VATS, pathology, and cytology findings constituted the reference standard. Results: In 26/44 (59%) patients, pleural biopsies were malignant. Only the size of left-sided pleural effusion (reader 1: rho= -0.39, p=0.01; reader 2: rho=-0.37, p=0.01) and presence of ascites (reader 1: rho=-0.33, p=0.03; reader 2: rho=-0.35, p=0.03) were significantly associated with solid pleural metastasis. Pleural fluid cytology was malignant in 26/35 (74%) patients. Only the presence (p=0.03 for both readers) and size (reader 1: rho=0.34, p=0.04; reader 2: rho=0.33, p=0.06) of right-sided pleural effusion were associated with malignant pleural effusion. Interobserver agreement was substantial (kappa=0.78) for effusion size and moderate (kappa=0.46) for presence of solid pleural disease. No other CT features were associated with malignancy at biopsy or cytology. Conclusion: In patients with advanced EOC, ascites and left-sided pleural effusion size were associated with solid pleural metastasis, while the presence and size of right-sided effusion were associated with malignant pleural effusion. No other CT features evaluated were associated with pleural malignancy.