IntroductionPleural fluid characteristics may be complimentary in diagnosing pleural disease but tissue histopathology remains the gold-standard for diagnosis, particularly in malignancy. We sought to understand how practice has changed over time with the incorporation of novel techniques in a high-volume centre.MethodsA retrospective study of all local anaesthetic thoracoscopies (LAT) and physician performed image guided pleural biopsies (IGPBx) with ultrasound at a single centre from 2014–2019.Results510 procedures were performed over this period; 67% were LATs (343/510) the remainder were IGPBx (167/510).The proportion of IGPBx rose from 31% of procedures per year in 2014 (26) to 45% of procedures per year in 2018 (44). The number of talc poudrages performed decreased from 46% in 2015 (29) to 9% in 2018 (5).IGPBx was used preferentially in cases of benign pleural disease with 61.2% (98) resulting in a benign diagnosis compared to 46.8% (153) in the LAT group (c2 1df = 8.9, p=0.003).A higher proportion of complications were seen in LATs overall (c2 1df = 8.0, p=0.005) with complications seen in 15% of case (53). The majority were related to pain control (17), followed by vasovagal episodes (8). IGPBx were associated with complications in 6.6% of cases (11) and were largely related to bleeding (7).The sensitivity of LAT biopsies for malignant pleural disease was 87%, compared to 78% for IGPBx. The negative predictive value of both were comparable at 90% for LAT and 87% for IGPBx (figure 1). The majority of false negative biopsies in both groups were seen in Mesothelioma; 11/18 (61.1%) in the LAT group and 9/14 (64.2%) in the IGPBx group.Abstract P203 Table 1Sensitivity/Specificity/PPV/NPV analysis LAT and IGPBx LAT +ve Malignant Pleural Disease -ve Malignant Pleural Disease IGPBX +ve Malignant Pleural Disease -ve Malignant Pleural Disease Biopsy +ve 123 1 PPV 0.99 Biopsy +ve 49 0 PPV 1.00 Biopsy -ve 18 160 NPV 0.90 Biopsy -ve 14 95 NPV 0.87 Sens 0.87 Spec 0.99 Sens 0.78 Spec 1.00 DiscussionPhysician performed IGPBx offers an alternative choice of procedure to LAT with comparable negative predictive values although direct comparison is limited due to the heterogenous patient groups they were performed in. IGPBx were associated with fewer complications and therefore may be suited to a frailer patient cohort. LAT biopsies have a higher diagnostic yield and therefore thoracoscopic biopsies remain the gold-standard for diagnosing malignant pleural disease.