A comprehensive comparison between TBI vs non-TBI-based conditioning regimen in pediatric patients with acute lymphoblastic leukemia: A systematic review and meta-analysis.

INTRODUCTION: We aimed to evaluate the efficacy, safety, and latent toxicity of total body irradiation (TBI)-based conditioning regimens compared to non-TBI regimens for pediatric patients (under 18 years old) with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: A systematic search was performed on MEDLINE, Scopus, WOS, and PMC. Also, a search for grey literature was performed on Google Scholar and relevant articles' references were included. Relevant articles which met the inclusion criteria were retrieved up to October 31th, 2022. CMA version 2 was used for the quantitative synthesis of the data. RESULTS: Eight studies on efficacy and safety of TBI and non-TBI as a conditioning regimen were analyzed and six comparative studies on late toxicity were investigated. The meta-analysis revealed a hazard ratio (HR) of 1.508 (95% CI 0.96-2.35) for overall survival (OS) in instances of non-TBI conditioning. Also, an HR of 1.503 (95% CI 1.006-2.25) for disease-free- survival (DFS) favoring TBI-based conditioning. Late complications were reported to be significantly higher in the TBI conditioning regimen group than in the non-TBI group. CONCLUSION: It appears that non-TBI regimens are as effective as TBI regimens in pediatrics with ALL regarding OS. Occurrence of latent toxicity is higher with TBI conditioning regimen. Conversely, TBI-based regimens are superior to non-TBI conditioning regimens regarding DFS. Considering all aspects, non-TBI conditioning regimens can be an alternative treatment option for pediatric ALL undergoing HSCT.

Fanconi anemia phenotypic and transplant outcomes' associations in Iranian patients.

Objectives: Fanconi anemia (FA) is a rare, heterogeneous, inherited disorder. Allogeneic hematopoietic stem cell transplantation (HSCT) represents the only therapeutic option to restore normal hematopoiesis. This study reports the outcomes of FA-HSCT patients and identifies factors, including clinical phenotype. Our team examined more than 95% of Iranian FA patients during the last decade. Study Design: One hundred and six FA patients (age range: 2-41) who underwent HSCT from March 2007 to February 2018 were enrolled. Clinical characteristics of genetic disease, pre-HSCT findings, HSCT indication, and long-term follow-up evaluated and recorded. Data were analyzed using SPSS 19.0. Results: The mean follow-up period for survivors was 36 months (range, 1-101). The 3-year overall survival (OS) and disease-free survival were 72.2% and 71.2%, respectively. The 3-year OS rate for patients with limited and extensive malformations was 78.8% and 56.6%, respectively (p = 0.025). Acute graft versus host disease incidence was 60.52% for patients with limited malformations versus 70% for patients with extensive ones (p = 0.49). Chronic graft versus host disease incidence for these two groups was 9.21% and 10%, respectively (p = 0.91). Conclusions: OS was not associated with each of the malformations singly; however, it was lower in the extensive group. The younger age of patients at the HSCT time leads to a higher OS. The differences in FA patients' outcomes and the various genotypes were probably related. These data provide a powerful tool for further studies on genotype-phenotype association with HSCT results.