Neurocognitive effects of Partial Brain Irradiation

In the Red Journal - 9402 was a randomized trial of RT +/- PCV for AO, but one of the strengths of the trial was that prospective analysis of neurocognition was built in. What I find interesting in this report is that both arms had a stable "Brain quality of life" through the follow up period even compared to baseline (though not surprisingly this did decline in the last year of life for those who died on trial). As such little is known on the long term effects of partial brain irradiation, this observation adds significantly to our understanding of this.

Link and Abstract

Cognition and Quality of Life After Chemotherapy Plus Radiotherapy (RT) vs. RT for Pure and Mixed Anaplastic Oligodendrogliomas: Radiation Therapy Oncology Group Trial 9402: "Purpose: Radiation Therapy Oncology Group 9402 compared procarbazine, lomustine, and vincristine (PCV) chemotherapy plus radiation therapy (PCV + RT) vs. RT alone for anaplastic oligodendroglioma. Here we report longitudinal changes in cognition and quality of life, effects of patient factors and treatments on cognition, quality of life and survival, and prognostic implications of cognition and quality of life.Methods and Materials: Cognition was assessed by Mini Mental Status Examination (MMSE) and quality of life by Brain-Quality of Life (B-QOL). Scores were analyzed for survivors and within 5 years of death. Shared parameter models evaluated MMSE/B-QOL with survival.Results: For survivors, MMSE and B-QOL scores were similar longitudinally and between treatments. For those who died, MMSE scores remained stable initially, whereas B-QOL slowly declined; both declined rapidly in the last year of life and similarly between arms. In the aggregate, scores decreased over time (p = 0.0413 for MMSE; p = 0.0016 for B-QOL) and were superior with age <50 years (p < 0.001 for MMSE; p = 0.0554 for B-QOL) and Karnofsky Performance Score (KPS) 80–100 (p < 0.001). Younger age and higher KPS were associated with longer survival. After adjusting for patient factors and drop-out, survival was longer after PCV + RT (HR = 0.66, 95% CI = 0.49–0.9, p = 0.0084; HR = 0.74, 95% CI = 0.54–1.01, p = 0.0592) in models with MMSE and B-QOL. In addition, there were no differences in MMSE and B-QOL scores between arms (p = 0.4752 and p = 0.2767, respectively); higher scores predicted longer survival.Conclusion: MMSE and B-QOL scores held steady in the upper range in both arms for survivors. Younger, fitter patients had better MMSE and B-QOL and longer survival."