Cherng, Hua-Ren R

Abstract Background Although there are data describing the onset of neurocognitive toxicity following radiation for patients with brain metastases, less is known about the potential for functional cognitive recovery (CR). This study sought to evaluate CR following neurocognitive function failure (NCF) in patients treated with stereotactic radiosurgery (SRS), whole-brain radiotherapy (WBRT), and hippocampal avoidance (HA)-WBRT. Methods A pooled analysis of 3 (NCCTG N107C/CEC.3, NCCTG N0574, and NRG CC001) clinical trials was performed. Patients with trial-defined NCF and longitudinal cognitive testing were included. The primary endpoint was time to CR, defined as patients no longer exhibiting a 1 or more standard deviation decline from baseline on any cognitive test. Results A total of 288 patients were included, with a median follow-up of 12.2 months. The cumulative incidence of CR was 38% (95% confidence interval [CI] = 32.5% to 43.9%) at 6 months after NCF. Incidence of CR was significantly improved with post-op SRS vs WBRT (hazard ratio [HR] = 2.68, 95% CI = 1.43 to 5.03, P = .002) and with SRS vs SRS+WBRT (HR = 2.35, 95% CI = 1.16 to 4.79, P = .008). On multivariable analysis, SRS was highly prognostic of CR compared with WBRT (HR = 2.42, 95% CI = 1.70 to 3.45, P < .0001). Meta-analysis demonstrated that conformal RT techniques (SRS or HA-WBRT) conferred a significantly higher rate of CR compared with WBRT (pooled HR = 2.12, 95% CI = 1.49 to 3.02, P < .001); 68% of patients had long-term sustained CR. Conclusions A sizeable proportion of patients who experience NCF following brain radiation eventually attain full and sustained CR, thereby highlighting that neurocognitive decline may not be permanent. The use of conformal radiation techniques results in greater rates of neurocognitive recovery.

Abstract Background EuroQoL EQ-5D-5L is a commonly used measure of health-related quality of life in clinical trials given the use of its index score as a measure of health utilities. It is unclear whether EQ-5D-5L is sensitive to changes in neurocognitive function and progression that occur following brain radiation. This study sought to evaluate the sensitivity of EQ-5D-5L in reflecting these changes. Methods A secondary analysis of NRG Oncology CC001 was performed. Mean EQ-5D-5L index and visual analog scale (VAS) score changes from baseline between groups of patients stratified by neurocognitive function and intracranial progression status were assessed. MD Anderson Symptom Inventory for brain tumor (MDASI-BT) symptom and interference items were also analyzed between groups. Results EQ-5D-5L mean index and VAS score changes between patients who had cognitive failure and those who had preserved cognition showed no statistically significant differences at any timepoint. In contrast, VAS changes at 4 months (1.61 vs -5.13, P = .05) and 6 months (8.17 vs −0.14, P = .04) were significantly improved in the patients who survived without intracranial progression. MDASI-BT cognitive factor scores were improved in the cohort of patients with preserved neurocognitive function at 2 months (1.68 vs 2.08, P = .05) and 4 months (1.35 vs 1.83, P = .04). MDASI-BT symptom interference was significantly associated with intracranial progression at 4 months, but not with neurocognitive status. Conclusion EQ-5D-5L index and VAS scores were not sensitive to neurocognitive changes that patients experienced, but VAS scores were sensitive to progression. This study challenges the routine use of EQ-5D as a quality of life metric in brain metastases clinical trials that are focused on preventing neurocognitive dysfunction. Trial Registration NCT# 02360215.

Abstract Background Hippocampal avoidant whole brain radiotherapy (HA-WBRT) is the standard of care for patients needing WBRT for brain metastases. This study, using existing data from NRG Oncology CC001 including baseline tumor characteristics and patient-reported MD Anderson Symptom Inventory-Brain Tumor (MDASI-BT) scores, sought to identify subgroups of patients that demonstrate differential neuroprotective treatment response to HA-WBRT. Methods An exploratory analysis of NRG CC001, a phase 3 trial in which 518 patients were randomly assigned to WBRT plus memantine or HA-WBRT plus memantine, was performed. Rates of neurocognitive function failure (NCFF) were estimated between subgroups and stratified by arm. Covariate and subgroup interaction with differential treatment response were calculated. Results The benefit of HA-WBRT on decreasing NCFF was seen in patients living ≥ 4 months (HR 0.75, 95% CI: 0.58–0.97, P = .03), whereas patients living < 4 months derived no significant neurocognitive benefit. A significant association between baseline MDASI-BT cognitive factor and treatment response (interaction P = .03) was identified. Patients with lower MDASI-BT scores (less patient-reported cognitive impairment) derived significantly greater benefit (HR = 0.64, 95% CI: 0.48–0.85, P = .002) compared to those with highest MDASI-BT scores (HR = 1.24, 95% CI: 0.76–2.04, P = .39). Tumor histology also had a significant interaction (P = .01) with treatment response. Primary lung histology patients derived cognitive failure risk reduction (HR = 0.58, 95% CI: 0.43–0.77, P = .0007) from HA-WBRT, in contrast to nonlung primary histology patients (HR = 1.15, 95% CI: 0.78–1.50, P = .48). Conclusions Differential neuroprotective response to HA-WBRT was identified in this analysis. Patients surviving ≥ 4 months derived benefit from HA-WBRT. There is evidence of heterogeneity of treatment effect for patients with less severe patient-reported cognitive impairment at baseline and those with primary lung histology.