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Journal of Clinical Oncology, 2006 ASCO Annual Meeting Proceedings (Post-Meeting Edition).
Vol 24, No 18S (June 20 Supplement), 2006: 9032
© 2006 American Society of Clinical Oncology
Effect of prophylactic cranial irradiation dose on CNS relapse, late cognitive decline and learning disabilities in children treated for acute lymphoblastic leukemia
M. M. Meshref,
N. Elshazly,
M. Nasr and
R. Abdelhai
Cairo University, Cairo, Egypt
9032
Background: Prophylactic cranial irradiation is still standard in treatment of high risk childhood acute lymphoblastic leukemia. In this study we assessed the effect of cranial irradiation dose of 1,800 cGy and 1200 cGy on CNS relapse as well as the late cognitive decline and learning disabilities in both groups versus a control group using neurophysiologic and psychometric studies. Methods: 42 patients treated from acute lymphoblastic leukemia and categorized to be at high risk of relapse were assessed in this study. 28 patients received prophylactic cranial irradiation at a dose of 1,800 cGy and 14 received a dose of 1,200 cGy. A control group of 42 age and sex matched normal children was also assessed. Visual and auditory P300 studies were carried out to assess high visual and auditory processing functions. Several selected subscales of Wechsler Intelligence scale for children were applied to both subgroups as well as the control group. Results: Mean age at receiving irradiation was 5.7 years. Mean testing age was 10 years. Mean follow up period was 4.6 years.There was one CNS relapse in the group who received 1,800 cGy (3.5%) and one in the group who received 1,200 cGy (7%). As compared to the control group the group of patient who received 1,800 cGy showed a high statistically significant delay in the latency and significant reduction in the amplitude of the Visual P300 (p <0.001, =0.01 respectively). The Auditory P300 showed a significant delay in latency (p=0.01). In the group receiving 1,200 cGy only the latency of the visual P300 was significantly affected(p=0.01). The other parameters in the 1,200 cGy subgroup were not significantly affected. As for the psychometric studies there were significant differences in several subscales between controls and 1,800 cGy subgroup namely in similarities, total performance and picture compilation which were not found between controls and 1,200 cGy subgroup. Conclusions: These findings reflects that there is impairment in the intellectual abilities as well as visual and auditory processing functions in the subgroup receiving 1,800 cGy compared to the controls which was much less in the subgroup receiving 1,200 cGy at no significant increased protection from CNS relapse.
No significant financial relationships to disclose.
Abstract presentation from the 2006 ASCO Annual Meeting
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