Height impairment after lower dose cranial irradiation in children with acute lymphoblastic leukemia

Purpose: The purpose of this study is to determine whether height measurements are affected by cranial radiation doses of 12-18-Gy.Patients and Methods: From 1997 to 2007, 23 children received cranial RT for T-cell or pre-B-cell acute lymphoblastic leukemia (ALL). Dose fractionation schemes included 18-Gy in 9 fractions (n-=-8), 18-Gy in 10 fractions (n-=-5), 12.6-Gy in 7 fractions (n-=-6), and 12-Gy in 8 fractions (n-=-4). These patients were matched and compared to a control group of 23 patients who had ALL but no cranial RT. Height z-scores at diagnosis and last follow-up were compared using the paired Student's t-test. Differences in z-scores according to host and treatment parameters were compared using the unpaired Student's t-test. Median follow-up for irradiated patients was 63.5 months while for unirradiated patients was 91 months.Results: The mean z-scores at initial diagnosis and last follow-up were 0.14 and -0.48 for patients receiving 12-12.6-Gy (P-=-0.016), -0.16 and -0.89 for 18-Gy (P-=-0.003), and 0.34 and 0.22 for no RT (P-=-0.62). For children receiving RT, the mean difference in z-scores at initial diagnosis and last follow-up was -0.67 while for those not receiving RT, it was -0.10 (P-=-0.043).Conclusion: Children receiving 12-18-Gy cranial RT for ALL were found to have height impairment compared to those not receiving RT.