BMET-05: NCCTG N0574 (ALLIANCE): A PHASE III RANDOMIZED TRIAL OF WHOLE BRAIN RADIATION THERAPY (WBRT) IN ADDITION TO RADIOSURGERY (SRS) IN PATIENTS WITH 1 TO 3 BRAIN METASTASES

BACKGROUND: WBRT significantly improves tumor control in the brain after SRS, yet the role of adjuvant WBRT remains undefined due to concerns regarding neurocognitive risks. METHODS: Patients with 1-3 brain metastases, each <3 cm by contrast MRI, were randomized to SRS alone or SRS + WBRT and underwent cognitive testing before and after treatment. The primary endpoint was cognitive progression (CP) defined as decline >1 SD from baseline in any of the 6 cognitive tests at 3 months. Time to CP was estimated using cumulative incidence adjusting for survival as a competing risk. RESULTS: 213 patients were enrolled with 2 ineligible and 3 cancels prior to receiving treatment. Baseline characteristics were well-balanced between study arms. The median age was 60 and lung primary the most common (68%). CP at 3 months was more frequent after WBRT + SRS vs. SRS alone (91.7% vs. 63.5% respectively, p = 0.0007). There was more deterioration in the WBRT + SRS arm in immediate recall (30% vs. 8%, p = 0.0043), delayed recall (51% vs. 20%, p = 0.0009), and verbal fluency (19% vs. 2%, p = 0.0098). After WBRT + SRS there was more deterioration in overall QOL (p = 0.001) and functional well-being (p = 0.006) at 3months. Intracranial tumor control at 3 and 6 months were 75.3% and 64.7% with SRS alone vs. 93.7% and 88.4% with SRS + WBRT (p < 0.0001). Median OS was 10.4 for SRS alone vs. 7.4 months for SRS + WBRT respectively (HR = 1.02, p = 0.92). CONCLUSIONS: Decline in QOL and cognitive function, specifically immediate recall, memory and verbal fluency, was more frequent with the addition of WBRT to SRS. Adjuvant WBRT did not improve OS despite better brain control. Initial treatment with SRS and close monitoring is recommended to better preserve cognitive function in patients with newly diagnosed brain metastases that are amenable to SRS.