MAGNETIC-RESONANCE-IMAGING AND MAGNETIC-RESONANCE ANGIOGRAPHY IN LONG-TERM SURVIVORS OF ACUTE LYMPHOBLASTIC-LEUKEMIA TREATED WITH CRANIAL IRRADIATION

Background. Successful treatment of acute lymphoblastic leukemia (ALL) has resulted in an increasing number of patients whose disease is cur ed, This treatment includes cranial irradiation as prophylaxis against central nervous system relapse, The late effects of irradiation are w ell documented, but their incidence is unknown, The authors investigat ed the late effects of this treatment modality further by scanning 35 long term survivors of ALL who received cranial irradiation, Methods, Thirty-five survivors of ALL with no known complication of treatment w ere included in this study. They were examined with magnetic resonance imaging (MRI) of the brain and magnetic resonance angiography (MRA) o f the circle of Willis, A control group of 24 patients who were cured of other childhood malignancies without exposure to cranial irradiatio n also were scanned, Results. Fifteen of 35 (43%) abnormalities were f ound in the study group versus 4/24 (17%) in the control group. Exclud ing minor atrophic changes that are known to be produced by irradiatio n and chemotherapy, there were 9/35 (26%) abnormalities in the study g roup and 1/24 (4%) in the control group (P < 0.05), These abnormalitie s included three tumors, a meningioma, a paranasal sinus rhabdomyosarc oma, and an anaplastic astrocytoma, In addition, there were two cases of large vessel vasculopathy, two small cystic infarcts, one diffuse w hite matter abnormality, and one cryptic vascular malformation, The ab normal control patient had a cerebellar infarct, Conclusion, Complicat ions of cranial irradiation in the treatment of ALL appear to be more frequent than currently are appreciated, That these complications incl ude tumors that are potentially treatable suggests that screening may be valuable for these patients.