Purpose: To evaluate the effects of limited field conventional cerebral radiotherapy (RT) on cognitive functions of adults.
Methods and materials: A prospective neuropsychological study was performed on 17 patients who underwent conventional limited field RT for a low-grade glioma or for a good-prognosis anaplastic glioma. Results were compared with 14 control patients with low-grade gliomas who did not receive radiotherapy.
Results: A transient significant decrease of performances for the Reaction Time test was observed at 6 months in the irradiated group with return to baseline values 12 months post-RT. Subsequently, no other significant changes were observed over a 48-month follow-up period in the irradiated and nonirradiated groups. Nonetheless, when the scores of each patient were considered over time instead of the mean values of the group, one irradiated patient (5.8%) experienced progressive deterioration while two irradiated patients (11.7%) experienced long-lasting improvement. Individual changes did not occur in the control group.
Conclusion: This study suggests that a transient early delayed drop of neuropsychological performances at 6 months is frequent following limited field conventional RT, but the risk of long-term cognitive dysfunction after irradiation is low, at least in the first 4 years after RT and when it is administered alone in young adults.