Neurocognitive Impact of Whole Brain Radiation on Patients With Brain Metastases: Secondary Analysis of RTOG BR-0018
This is the second report from a study on the ability to evaluate neurocognitive functioning after whole brain radiotherapy. This report specifically addresses the results of these evaluations. Participants were recipients of whole brain radiation therapy (WBRT) and underwent 6 neurocognitive and quality-of-life tests prior to WBRT, after completion, and 1 month after completion. The tests looked at memory, attention, cognition, verbal learning and vocabulary, speed of performance, mood, anger, depression, vigor, fatigue and confusion.
The analysis includes 55 patients. WBRT has been shown to reduce recurrence rates for patients with brain metastases and decrease the likelihood that these patients will die of the brain involvement. However, many physicians are concerned that WBRT leads to cognitive side effects and dementia-like symptoms in patients receiving treatment. Although patients with brain metastases typically do not live long enough to experience late radiation toxicity (months to years after therapy), concerns of acute cognitive toxicity have hindered patient referrals to radiation oncologists for delivery of WBRT in this patient population.
In this study, some testing showed a decline at the end of treatment, but by one month following WBRT, the majority of neurocognitive tests showed improvement over baseline. Mood and quality-of-life scores remained stable or improved in the majority of patients, as well.
In a recently published phase III trial involving 208 patients with brain metastases, tumor growth was shown to adversely affect neurocognitive function more strongly than the WBRT (Li J, et al. J Clin Oncol . 2007;25(10):1260-6.). The RTOG BR-0018 analysis gives additional credence to the findings by Li and colleagues and demonstrates that WBRT can improve quality-of-life and neurocognitive indices above baseline by one month following WBRT in patients with brain metastasis.
Future investigation should control for corticosteroid (dexamethasone, prednisone) usage due to their ability to impact neurocognitive functioning and mood. Additionally, as results were only reported at up to one month following WBRT, additional investigation will be needed to evaluate for late effects of irradiation on neurocognitive functioning and patient quality of life.
Partially funded by an unrestricted educational grant from Bristol-Myers Squibb.