Chest CT Has Higher Yield for Infection than CT Sinus in Febrile Neutropenic Patients

Objective: Chest and sinus CT imaging among cancer patients undergoing chemotherapy and bone marrow transplant in the setting of neutropenic fever is not uncommon, yet the utility of routine imaging surveillance remains unclear. We aim to compare the rates of acute infection detected on CT chest and CT sinus exams performed in this clinical setting. Methods: Reports of 1059 consecutive CT chest and sinus examinations for the clinical indication of neutropenic fever on 262 patients performed between January through June 2017 were retrospectively reviewed. Infection as reported was characterized as acute or worsening, improving, stable, indeterminate or negative. Results were tabulated and Pearson's chi-square test was used for comparison analysis. Results: Absence of infection on CT sinus was significantly higher than CT chest (86.1% vs. 58.5%; P<0.001). Conversely, CT chest had significantly higher incidence of acute or worsening infection than CT sinus (28.7% vs. 11.6%; P<0.001). CT chest also showed significantly higher incidence of improving infection compared to CT sinus (6.2% vs. 1.1%; P<0.001). There was no significant difference between incidence of stable infection on CT chest and CT sinus (1.1% vs. 0.2%; P=0.059). Infection was indeterminate in 5.5% of CT chest vs. 1% on CT sinus (P<0.001). Conclusions: CT chest showed significantly higher diagnostic yield for acute infection than CT sinus, suggesting that sinusitis is less likely to be the source of fever than chest infections in febrile neutropenic patients. The majority of CT studies showed absence of infection, raising the question of the overall utility of routine surveillance CT imaging among this subset of patients.