***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 PURPOSE To prospect ively evaluate the association between hippocampal dose and long-term neurocognitive function ( NCF ) impairment for benign or low- grade adult brain tumors treated with fractionated stereotactic radiotherapy ( FSRT ) . METHODS AND MATERIAL S Adult patients with benign or low- grade adult brain tumors were treated with FSRT per institutional practice . No attempt was made to spare the hippocampus . NCF testing was conducted at baseline and 18 months follow-up , on a prospect i ve clinical trial . Regression-based st and ardized z scores were calculated by using similar healthy control individuals evaluated at the same test-retest interval . NCF impairment was defined as a z score ≤-1.5 . After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas , dose-volume histograms were generated for the left and right hippocampi and for the composite pair . Biologically equivalent doses in 2-Gy fractions ( EQD(2 ) ) assuming an α/β ratio of 2 Gy were computed . Fisher 's exact test and binary logistic regression were used for univariate and multivariate analyses , respectively . Dose-response data were fit to a nonlinear model . RESULTS Of 29 patients enrolled in this trial , 18 completed both baseline and 18-month NCF testing . An EQD(2 ) to 40 % of the bilateral hippocampi > 7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List ( WMS-WL ) delayed recall ( odds ratio [ OR ] 19.3 ; p = 0.043 ) . The association between WMS-WL delayed recall and EQD(2 ) to 100 % of the bilateral hippocampi > 0.0 Gy trended to significance ( OR 14.8 ; p = 0.068 ) . CONCLUSION EQD(2 ) to 40 % of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low- grade adult brain tumors . Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold , patients should be enrolled in ongoing prospect i ve trials of hippocampal sparing during cranial irradiation to confirm these preliminary results The accurate interpretation of serial neuropsychological testing is a fundamental activity of neuropsychologists in clinical and research setting s. Although prior research supports the construct validity of several individual tests for the reliable measurement of cognitive change , neuropsychologists are often interested in detecting changes in cognitive functioning across a battery of tests . In the present study , we examined the specificity of a modified Reliable Change Index ( RCI ) methodology applied across a focused battery of commonly used neuropsychological tests . Fifty-seven healthy controls underwent neuropsychological assessment at two time points separated by approximately 1 year . Test-retest reliability coefficients and st and ard RCI confidence intervals for the individual tests were broadly comparable with prior research in healthy population s. Battery change scores were generated by calculating z-scores of change for each individual test , which were summed across the entire test battery . The RCI methodology was applied to the summed z-score to provide a 90 % confidence interval as an indicator of overall cognitive stability . These battery RCI normative st and ards demonstrated adequate specificity when applied to 29 persons with HIV-1 infection who were classified as medically and neurologically stable . Findings from this study may be useful for both clinicians and research ers seeking normative st and ards for determining reliable changes in performance across a commonly used battery of neuropsychological tests Previous research indicates that practice effects are large with repeated versions of memory tests . In contrast , administrations of the same tests using alternate forms typically yield much smaller practice effects . However , most studies do not compare alternate- and same-form conditions directly , and differ widely in terms of test-retest interval , modality of stimuli ( verbal , spatial ) , format of the memory test , and number of examinations . The present study investigated practice effects during repeated administrations of verbal and nonverbal memory tests which have the same administration format . Two groups of healthy participants , matched for age , education , estimated IQ , and baseline memory test performance , were assigned to either a same- or alternate-forms condition . Participants taking the same form every two weeks improved significantly over four sessions . Participants completing alternate forms of the nonverbal memory test produced a small practice gain , but the verbal memory test was resistant to practice effects when alternate forms were used 
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Conclusions In general , the results show little to no objective cognitive decline up to 4 months after SRS compared with WBRT .
This study is expected to improve the quality of decision-making and maximize clinical outcomes for each individual patient