GALLIUM SCANNING CAN INFLUENCE TREATMENT DECISIONS IN PATIENTS WITH INTERSTITIAL LUNG DISEASE

SESSION TITLE: Tuesday Electronic Posters 3 SESSION TYPE: Original Inv Poster Discussion PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM PURPOSE: Interstitial lung disease (ILD) is a heterogeneous group of disorders with a variable degree of inflammation and fibrosis. Although evaluation and management of ILD have advanced with high-resolution computed tomography (HRCT), making treatment decisions is still challenging, especially when there is uncertainty whether active inflammation is present. Studies before the advent of HRCT suggested that gallium scanning, a noninvasive imaging to detect inflammation, correlate well with lung biopsy and bronchoalveolar lavage in ILD; however, the utility of gallium scanning is unestablished. We aimed to investigate whether performing gallium scanning in patients with ILD can influence treatment decisions. METHODS: This is a single institution descriptive study. From our ILD registry, we identified patients with non-sarcoidosis ILD who had one or more gallium scans between 2014 and 2018. We collected patient data: ILD type; gallium scan result; presence of HRCT findings indicating inflammation (ground-glass opacities or consolidation); treatment decisions made immediately after gallium scanning; and occurrence of clinical decline (decline in predicted forced vital capacity by 10%, death or lung transplantation) during the follow-up. The data were described according to results of gallium scanning. RESULTS: Forty-seven patients (20 with connective tissue disease-associated ILD (CTD-ILD), nine chronic hypersensitivity pneumonitis (CHP), two idiopathic interstitial pneumonia, six other ILD and 10 undifferentiated ILD) had 48 gallium scans and were included in our study. Of the 48 gallium scans, the result was positive in 15 (31%). In the 15 cases, 12 had HRCT findings indicating inflammation, seven had change in treatment (all with an increase in immunosuppressant, including one with concurrent initiation of anti-fibrotic) and six had clinical decline; in the other 33 cases with negative gallium scanning (including two negative gallium scans in one patient), 21 had HRCT findings indicating inflammation, 13 had change in treatment (seven with an increase in immunosuppressant, five with decrease in immunosuppressant, two with initiation of anti-fibrotic) and 24% had clinical decline. Notably, in 20 cases with CTD-ILD, eight had change in treatment and one of them had clinical decline; in nine with CHP, three had change in treatment and none of them had clinical decline. CONCLUSIONS: Gallium scanning, in adjunct with HRCT, appears to help clinicians make reasonable treatment decisions in patients with ILD. Its clinical utility may be more pronounced in CTD-ILD and CHP. CLINICAL IMPLICATIONS: Clinicians should consider performing gallium scanning in patients with ILD when there is uncertainty whether active inflammation is present. DISCLOSURES: No relevant relationships by Michael Chung, source=Web Response No relevant relationships by Sakshi Dua, source=Web Response No relevant relationships by Tetsuro Maeda, source=Web Response No relevant relationships by Aditi Mathur, source=Web Response Consultant relationship with Boerhinger Ingelheim Please note: $5001 - $20000 Added 03/17/2019 by Maria Padilla, source=Web Response, value=Consulting fee Speaker/Speaker's Bureau relationship with Genentech Please note: $5001 - $20000 Added 03/17/2019 by Maria Padilla, source=Web Response, value=Honoraria