Aims:
Concerns regarding neurocognitive function (NCF) after whole brain radiotherapy (WBRT) exist. This trial compared WBRT vs observation (OBS) following local treatment in patients with one to three melanoma brain metastases. Here we present the NCF results.
Methods:
Objective NCF was evaluated in English speakers at baseline, then two-monthly. Primary outcome was change in delayed recall at four months on the Hopkins Verbal Learning Test-Revised (HVLT-R). Other NCF tests were also performed. A mixed linear model calculated the effect of intervention on relative raw scores, adjusted for baseline score and time. Cognitive failure was determined by Reliable Change Index; global cognitive impairment was defined as Global Deficit Score >0.5. Analysis was by intention-to-treat, with nominal two-sided significance level 5%.
Results:
207 patients were randomised (100 WBRT, 107 OBS) from 31 sites in 3 countries. NCF testing was completed by 73 WBRT and 70 OBS patients at baseline. Patients had similar characteristics.
OBS group had greater relative improvement in HVLT-R from baseline at every timepoint. At four months, delayed recall declined 2.7% from baseline in WBRT but improved by 20.9% in OBS; overall adjusted average intervention effect 23.6% (95%CI 9.0-38.2%; p=0.0018). Significant effects were seen between groups at four months in HVLT-total recall and delayed recognition, the overall adjusted average intervention effects were 8.3% (95%CI 0.4-16.1%; p=0.0397) and 25.0% (95%CI 14.3-35.7%; p<0.0001) respectively. There were no significant differences in time to cognitive failure (log-rank p=0.44), or proportions with global cognitive impairment at four months (OBS 32% vs WBRT 53%; p=0.11). Cognitive decline in T-scores, baseline to four months, of 1SD in at least one NCF test occurred in 24/38 (63%) WBRT vs 11/25 (44%) OBS (p=0.13).
Conclusion:
Cognitive impairment was common in both groups but greater memory decline occurred in patients receiving WBRT.