Estimation of iron overload with T2*MRI vs. serum ferritin in children
treated for hematological malignancies
Abstract
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
(p<0.001). MIC lacked correlation with SF or LIC. The number
of red-cell units transfused and duration from last transfusion
correlated with SF (p=0.001, 0.002) and LIC (p=0.012, 0.005). SF
>500 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.