***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND To determine the protective effects of memantine on cognitive function in patients receiving whole-brain radiotherapy ( WBRT ) . METHODS Adult patients with brain metastases received WBRT  and were r and omized to receive placebo or memantine ( 20 mg/d ) , within 3 days of initiating radiotherapy for 24 weeks . Serial st and ardized tests of cognitive function were performed . RESULTS Of 554 patients who were accrued , 508 were eligible . Grade 3 or 4 toxicities and study compliance were similar in the 2 arms . There was less decline in delayed recall in the memantine arm at 24 weeks ( P = .059 ) , but the difference was not statistically significant , possibly because there were only 149 analyzable patients at 24 weeks , result ing in only 35 % statistical power . The memantine arm had significantly longer time to cognitive decline ( hazard ratio 0.78 , 95 % confidence interval 0.62 - 0.99 , P = .01 ) ; the probability of cognitive function failure at 24 weeks was 53.8 % in the memantine arm and 64.9 % in the placebo arm . Superior results were seen in the memantine arm for executive function at 8 ( P = .008 ) and 16 weeks ( P = .0041 ) and for processing speed ( P = .0137 ) and delayed recognition ( P = .0149 ) at 24 weeks . CONCLUSIONS Memantine was well tolerated and had a toxicity profile very similar to placebo . Although there was less decline in the primary endpoint of delayed recall at 24 weeks , this lacked statistical significance possibly due to significant patient loss . Overall , patients treated with memantine had better cognitive function over time ; specifically , memantine delayed time to cognitive decline and reduced the rate of decline in memory , executive function , and processing speed in patients receiving WBRT . RTOG 0614 , Clinical Trials.gov number CT00566852 
    Output:
    
None of the RCTs with altered WBRT dose-fractionation schemes as compared to st and ard ( 3000 cGy in 10 daily fractions or 2000 cGy in 4 or 5 daily fractions ) found a benefit in terms of overall survival , neurologic function , or symptom control .
Radiosurgery boost with WBRT may improve local disease control in selected participants as compared to WBRT alone , although survival remains unchanged for participants with multiple brain metastases .
The addition of WBRT to radiosurgery improves local and distant brain control but there is no difference in overall survival .
It may be that supportive care alone , without WBRT , is appropriate for some participants , particularly those with advanced disease and poor performance status