Utility of Routine Computed Tomography Screening before Hematopoietic Stem Cell Transplantation in Pediatric Patients with Non-Malignant Disorders

Introduction Recipients of hematopoietic stem cell transplantation (HSCT) are at significant risk for toxicity following the procedure. In these immunocompromised patients, infections frequently complicate the transplant course, adding to morbidity and mortality of this population. Therefore, clinicians often feel the need to screen patients for preexisting infections to reduce the risk of post-HSCT complications, for which computed tomography (CT) imaging of the sinuses, chest, and abdomen/pelvis is often performed. Although this imaging may detect an infection, it increases the patient's radiation exposure, and it may complicate the scheduling of the pre-HSCT evaluation. Also, potential imaging artifacts may lead to unnecessary medical evaluations or delays in HSCT. Moreover, patients with non-malignant disorders as indication for HSCT are not as likely to have significant infection risk prior to transplant, compared to those with malignant conditions who are more severely immunocompromised. Methods After institutional review board approval, a retrospective study of patients who received HSCT at Children's Hospital of Pittsburgh from 2011 to 2017 was conducted. Results Of the 80 eligible patients, those who received chemotherapy prior to evaluation for HSCT, and patients who did not have CT scanning done as part of pre-HSCT evaluation were excluded. Thus, 55 subjects were included in this analysis. A univariate logistic analysis was performed to determine potential predictors of abnormal sinus, chest, abdomen/pelvis CT scans. Overall, 27 of 148 CT scans (18%) had positive findings. Of the 20 patients who had additional evaluation done based on these findings, 11 (55%) were related to chest CT findings, compared to 5 (25%) and 4 (20%) related to sinus and abdomen/pelvis CT, respectively. There were no variables that could predict positive findings on sinus and abdomen/pelvis CT scans. However, significant findings on chest CT scans were associated with certain predictors such as age (18 and older), graft type (peripheral blood) and pertinent infection history. The 5-year overall survival (OS) for patients with positive chest CT findings was 62.5%, in comparison to 91.5% for those with negative chest CT findings (P=0.049, OR=6.45). Conclusion Our findings suggest that routine pre-HSCT CT screening in pediatric patients with non-malignant disorders rarely identifies abnormalities that lead to significant changes in clinical management. This study did not identify predictors for positive sinus and abdomen/pelvis CT scans. For chest CT, age, graft type and previous infection history were found to be predictors for abnormal findings. Moreover, patients with positive pre-HSCT CT scans were found to have lower survival rate, correlating to their higher prevalence of previous infection history.