1740. Title: Outcomes of a Clinical Algorithm for the Early Diagnosis and Treatment of Invasive Fungal Sinusitis among Children with Hematologic Malignancy or Prior Hematopoietic Stem Cell Transplantation

BACKGROUND: Invasive fungal sinusitis (IFS) is a cause of significant morbidity and mortality among children with hematologic malignancy and hematopoietic stem cell transplant (HSCT) recipients, with an estimated mortality of 18–80%. Since 2007, our center has employed a clinical algorithm for the early detection and treatment of IFS among children with prolonged febrile neutropenia. METHODS: We reviewed all EORTC defined cases of proven IFS among children with underlying hematologic malignancy or prior HSCT admitted to our institution between July 1, 2004 and December 31, 2018, and compared clinical characteristics and outcomes (including underlying malignancy, chemotherapy regimen at the time of viremia, absolute neutrophil count, absolute lymphocyte count, treatment regimens, and 6 month mortality) between the pre (July 1, 2004–December 31, 2006) and post-protocol (January 1, /2007–December 31, 2018) periods. RESULTS: We identified 33 cases of proven IFS during the study period, with 6 in the pre-protocol and 27 in the post-protocol period. The most common underlying primary diagnosis was acute lymphoblastic leukemia (ALL) at > 50% with 8% of individuals with prior HSCT. Twenty-five cases (92%) during the protocol period were diagnosed via nasal endoscopy per protocol, with 17 (63%) reporting no clinical complaints of sinusitis. Median absolute neutrophil count (ANC) at the time of IFS diagnosis was 155/mm3 (IQR 0 – 375/ mm3; n = 12) with median duration of neutropenia 16.5 days (IQR 10.5–18.25, n = 12) at the time of diagnosis. Most individuals required one definitive debridement. Isolated fungal specimens included Bipolaris spp. (24%), Aspergillus spp. (20%), Curvularia spp. (20%), with Fusarium and Exserohilum spp. each at 12%, and Rhizopus spp. At least one patient had a co-infection with more than one fungal species. Pre-protocol cause-specific mortality at 6 months was 33.3% compared with 14.8% (P = 0.29) in the post- protocol period. CONCLUSION: IFS is a cause of significant morbidity and mortality among children with hematologic malignancy or prior HSCT. An aggressive protocol with early nasal endoscopy and targeted debridement may help decrease morbidity and mortality associated with this entity. Additional well-designed studies are needed to assess the potential benefits of this approach in the diagnosis and management of IFS among high-risk children. [Image: see text] DISCLOSURES: All authors: No reported disclosures.