Estimation of iron overload with T2*MRI vs. serum ferritin in children treated for hematological malignancies

Background: Iron overload may contribute to complications in childhood cancer survivors. Methodology. Patients treated for hematological malignancy, ≥6 months from the end of therapy, who had received ≥5 red-cell transfusions were enrolled in the cross-sectional study. Iron-overload was estimated by serum ferritin (SF) and T2*MRI. Results. Forty-five survivors were enrolled among 431 treated for hematological malignancies. The median age at diagnosis was 7-years. The median number of red-cell units transfused was 8 (IQR 7, 10). The median duration from the end of treatment was 15 months (IQR 8.75, 25). An elevated SF (>1000 ng/ml), elevated liver iron concentration (LIC) and myocardial iron concentration (MIC) were observed in 5 (11.1%), 20 (45.4%), and 2 (4.5%) patients, respectively. All survivors with SF >1000 ng/ml had elevated LIC. The LIC correlated with SF (p500 ng/ml predicted elevated LIC with sensitivity/specificity of 80%/79%. A cut-off of 8 units of red-cells predicted elevated LIC with sensitivity/specificity of 95%/49.8%. Conclusions. Iron overload in survivors of hematological malignancies who had received ≥5 red-cell transfusions, estimated by SF, LIC, and MIC was 11.1%, 45.4%, and 4.5%. We suggest screening by SF for survivors who have received >8 transfusions. If SF is 500-1000 ng/ml, a T2*MRI is useful for estimating LIC. A T2*MRI can be avoided if SF exceeds 1000 ng/ml, as LIC will be expected to be elevated.