Background: Whole brain irradiation is associated with late adverse events as memory and learning decline due to damage of the hippocampus. The primary objective is to assess memory changes for patients treated with hippocampal sparing IMRT. The secondary objectives are to evaluate local recurrence rate within the hippocampus, response rate and assess time to radiological progression.
Methods: Patients were randomized into two groups, the first received conventional whole brain radiotherapy and the second received hippocampal sparing whole brain IMRT, each received 30 Gy over 10 fractions. Patients had baseline memory assessment using Hopkins verbal learning test Revised before and 4 months after radiotherapy and MRI brain before treatment and every 2 months thereafter.
Results: 41 patients were assessed, first group (n=20) and second group (n=21). The median follow up duration was 6 months. Regarding neurocognitive outcomes, the first group showed statistically significant decline for total and delayed recalls obtained 4 months after radiotherapy compared to the base line level (p= 0.009 and 0.001) while hippocampus sparing group had no statistically significant differences between pre and post treatment (p= 0.746 and 0.478). No statistically significant differences between both groups regarding partial response rate (40% vs 42.8%) (p= 0.5), median time to radiological progression (3 vs 4 months) (p=0.5) or acute GI – II toxicities (80% vs 61.9%) for group I and II respectively. None of group II patients relapsed within the hippocampus.
Conclusions: Hippocampal sparing WBRT is an effective and feasible technique for preservation of neurocognitive functions while maintaining intracranial control.