Evaluation of the potential of inducing neurocognitive changes in patients receiving intracranial stereotactic irradiation for benign tumors: a preliminary study.

Objective: To fully evaluate the efficacy of intracranial stereotactic irradiation, tumour control needs to be assessed in conjunction with the effects of radiation on normal tissue and the potential for changes in physiology, cognition and quality of life. This prospective pilot study investigated whether intracranial stereotactic irradiation induces cognitive changes in patients with cranial and base of skull lesions that did not directly involve the brain parenchyma. The value of a software-based psychometric approach to neurocognitive testing was also examined.

Methods: Thirty-four patients were enrolled, with 23 having sufficient data for statistical analyses. Pre-treatment baseline composite test score results for memory, attention, motor, language, executive function, and social function were compared to post-radiotherapy scores at final evaluation (median follow-up 24 months, range 12-59 months). Testing was done using the Brain Resource Company® (BRC) Internet accessed cognitive function test batteries, namely the WebNeuro® and IntegNeuro®, and the BRISC® (Brain Resource Inventory for Social Cognition).

Results: Quantitative results revealed no overall decline in cognitive function, and improvement in both executive functioning (p = 0.0002) and social functioning (p = 0.0016). Qualitatively, 6 patients at the final endpoint, and 4 patients at 12 months, were found to have a decline in one or more domains of function; with some of the patients who declined also showing improvement in certain domains.

Conclusion: Overall, no statistically significant evidence of cognitive decline was observed following intracranial stereotactic irradiation, at either 12 months or beyond.