Retrospective analysis of the sensitivity of reporting of thoracic computed tomography for pleural malignancy: an Australian multi-centre study.

Background: Contrast-enhanced computed tomography (CE-CT) is crucial in the early detection of malignant pleural effusion (MPE) and has significant impacts on diagnosis, staging and guiding procedural intervention. In real world practice, the sensitivity of CE-CT for MPE is significantly lower than initially described in the literature. We aim to assess the sensitivity of CE-CT reporting in assessment of suspected MPE in a real-world setting. Methods: A multi-centre retrospective review of pleural procedures in the years 2019-2020 at two tertiary centres (John Hunter Hospital, Calvary Mater Hospital) in Newcastle, Australia was performed. Patients with new MPE and a CT performed before histocytological confirmation of malignancy were included. CT reports were reviewed based on the use of pre-determined terminology indicating MPE. Results: A total of 101 patients were included for analysis. Sixty-eight studies were arterial phase, 25 were CT pulmonary angiograms and 2 were delayed venous phase. Seventy-one patients had reports indicating a malignant cause, yielding a sensitivity of 70% [95% confidence interval (CI): 61-78%]. The sensitivity was similar regardless of the contrast phase used. When using only the presence of Leung criteria the overall sensitivity dropped to 42% (95% CI: 32-51%) with a greater decrease seen especially with CT pulmonary angiogram (sensitivity 16%, 95% CI: 6-35%). Conclusions: This is, to our knowledge, the first evaluation of CE-CT use and its sensitivity in MPE assessment outside of Western Europe. This study highlights the limitations of CT in diagnosing MPE and supports early histocytological sampling. Further studies to evaluate the role of CE-CT in the pleural diagnostic pathway are needed.