2317 - Cardiovascular Outcomes Following Total Body Irradiation (TBI) in Children:A Systematic Review and Metanalysis

Purpose/Objective(s): Total body irradiation (TBI), an essential component of preparing children for stem cell transplants, has been associated with adverse cardiovascular (CV) outcomes in this population, including hypertension (HTN), heart disease, echocardiographic abnormalities, and valvular dysfunction. This systematic review aims to examine the CV outcomes linked to TBI in children.

Materials/Methods: A systematic search of PubMed, Embase, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Central Register of Controlled Trials identified articles evaluating CV outcomes following TBI in pediatric patients (under 21 years old), using Rayyan QCI. The quality of included studies was assessed for risk of bias using the National Institutes of Health tool. To evaluate the relationship between TBI and CV outcomes, we conducted a meta-analysis of odds ratios (OR) for outcomes reported in 3 or more articles, using both proportions and ORs from individual studies (Table 1). Meta-regression was then performed to assess the impact of treatment-related characteristics on the association between TBI and various CV outcomes.

Results: After reviewing 1,182 titles & abstracts, we identified 29 articles encompassing 21,929 patients that met our inclusion criteria. Among the 5,765 patients treated with TBI across these 29 articles, radiation data was available for 878 (15.2%). For the 7.3% of patients treated with TBI for whom cardiac outcomes were reported, the most commonly assessed outcomes were hypertension (HTN) (n=12), echocardiographic dysfunction (ED) (n=9), and metabolic syndrome (MS) (n=5). TBI significantly increased the odds of HTN (OR 2.17, 95% CI 1.64 – 2.87, p<0.05), ED (OR 4.48, 95% CI 2.52 – 7.97, p<0.05), & MS (OR 6.12, 95% CI 4.21 - 8.90, p<0.05). Among the eight studies that reported ORs between TBI and ED, a follow-up period greater than 10 years was significantly associated with a higher OR (mean difference in log OR = 1.54, 95% CI 0.00 - 3.07, p = 0.05).

Conclusion: TBI in pediatric patients significantly increases the risk of adverse CV outcomes, with TBI-treated children having notably higher odds of developing HTN, ED, & MS. Extended monitoring for CV health in this population is required, with further research necessary to define factors associated with TBI-induced cardiac toxicity and establish dose-response relationships.