Striking regression of temporal lobe necrosis following radiotherapy for nasopharyngeal carcinoma in a clinical trial of anti-mycobacterium therapy

The mechanism of radiation-induced delayed brain injuries remains poorly understood, and few treatment options are available. The aim of this study was to investigate whether temporal lobe necrosis can be reversed by anti-mycobacterium therapy (AMT). We conducted this prospective, controlled study in southern China. Ten patients with symptomatic delayed radiation injury were monitored during AMT and compared with a control group of 11 patients who received current standard therapies. Activities of daily living were assessed by the Barthel Index (BI) at study entry and after 2 years of therapy. Magnetic resonance imaging (MRI) was performed before treatment, and changes were monitored during the study. Kaplan–Meier analysis was employed to delineate time-related mortality. A significant treatment effect was observed in the AMT group. The patients’ headaches, seizures, dizziness, and cognitive deterioration rapidly improved. BI improved in the AMT treatment group compared with the control group after 2 years (Mann–Whitney U test; P=0·001). Abnormalities of the temporal lobes, observed by MRI, markedly decreased over time in eight patients, whereas in the control group significant BI deterioration was observed (Wilcoxon signed-rank test; P=0·003) and the patients did not show favorable MRI changes. By 24 months, there was a significant difference between the AMT and control groups with respect to survival time (log-rank test; P=0·011). The results of the present study suggest that radiation necrosis of the brain can be successfully managed by AMT. These findings must be confirmed in large, double-blind, randomized clinical trials.