The value of 18 F‑FDG PET/CT in the prediction of clinical outcomes of patients with acute leukemia treated with allogeneic hematopoietic stem cell transplantation

The present study aimed to determine whether 18F-FDG PET/CT performed before and/or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) can predict clinical outcomes in acute leukemia (AL). A total of 79 examinations comprising 72 patients with AL who underwent 18F-FDG PET/CT before and/or after allo-HSCT were retrospectively enrolled between January 2011 and January 2019. Outcomes were assessed using overall survival (OS) and disease-free survival (DFS). A total of 63 examinations were PET-positive, while 16 examinations were PET-negative. Increased BM and splenic 18F-FDG uptake were observed in 24 (19/79) and 14% (11/79) of examinations, respectively. 18F-FDG-avid lymph nodes were observed in 38% (30/79) of examinations. ENEMES involvement was detected in 44% (35/79) of examinations. The presence of ENEMES involvement [OS hazard ratio (HR), 6.399; 95% confidence interval (CI), 1.843-22.224; P=0.003; post-HSCT OS: HR, 7.203; 95% CI, 1.510-34.369; P=0.013; DFS HR, 3.671; 95% CI, 1.145-11.768; P=0.029], post-transplantation minimal residual disease (DFS HR, 4.381; 95% CI, 1.594-12.040; P=0.004; pre-HSCT OS HR, 11.455; 95% CI, 1.336-98.179; P=0.026) and disease status (OS HR, 0.330; 95% CI, 0.128-0.848; P=0.021; post-HSCT OS HR, 0.195; 95% CI, 0.050-0.762; P=0.019; DFS: HR, 0.278; 95% CI, 0.091-0.851; P=0.025) could serve as an adverse prognostic factor in patients with AL treated with allo-HSCT. 18F-FDG PET/CT before and/or after allo-HSCT was a predictor for OS and DFS in patients with AL. ENEMES involvement detected using 18F-FDG PET/CT may help identify patients with AL who are likely to have unfavorable clinical outcomes.