Screening Chest CT Prior to Allogenic Hematopoietic Stem Cell Transplantation

Abstract

Pulmonary complications constitute a major cause of morbidity and mortality in the post-allogenic hematopoietic stem cell transplant (alloHSCT) period. While Chest X-ray (CXR) is customarily used for screening, we have utilized chest computed tomography (CT). To characterize the prevalence of abnormalities and explore their impact on alloHSCT eligibility and outcomes post-transplant, we conducted a retrospective analysis utilizing real-world data collected at our center for adult patients who were evaluated for alloHSCT from January 2013 through December 2020 and identified 511 eligible patients. The most common primary disease was acute myeloid leukemia in 49% of patients, followed by myelodysplastic syndrome in 23%, lymphoma in 11%, and acute lymphocytic leukemia in 10%. Abnormal screening chest CT was found in 199 patients (39%). The most frequent detected abnormality was pulmonary nodule in 78 patients (35%), followed by consolidation in 42 (19%), ground-glass opacification in 33 (15%), bronchitis and bronchiolitis in 25 (11%), pleural effusions in 14 (6%), and new primary cancer in 7 (2%). CXR detected abnormalities in only about half of the patients (48%) with an abnormal chest CT. Among 199 patients with abnormal chest CT, 98 patients (49%) underwent further assessment and/or intervention before transplant. The most common work up was pulmonary consultation in 32%, infectious diseases consultation in 24%. Lung biopsy was obtained in 20% and antimicrobial therapy was initiated after confirming an infection diagnosis in 20% of patients. Patients with abnormal chest CT demonstrated worse overall survival (P= 0.032), non-relapse mortality (P=0.015), and pulmonary related death (P < 0.001) compared to those who had normal chest CT. Our study suggests that pre-transplant screening chest CT is beneficial in uncovering invasive infections and underlying malignancies and allows appropriate interventions before alloHSCT to prevent potentially serious post-transplant complications without causing a delay in alloHSCT. Nevertheless, abnormal CT findings prior to transplant may be associated with overall worse prognosis.