Stereotactic Radiosurgery With or Without Whole Brain Radiation Therapy for Limited Brain Metastases: A Secondary Analysis of the North Central Cancer Treatment Group N0574 (Alliance) Randomized Controlled Trial.
PURPOSE To determine whether whole brain radiation therapy (WBRT) is associated with improved overall survival among non small cell lung cancer (NSCLC) patients with favorable prognoses at diagnosis. METHODS AND MATERIALS In the N0574 trial, patients with 1 to 3 brain metastases were randomized to receive stereotactic radiosurgery (SRS) or SRS plus WBRT (SRS WBRT) with a primary endpoint of cognitive deterioration. We calculated diagnosis specific graded prognostic assessment (DS GPA) scores for NSCLC patients and evaluated overall survival according to receipt of WBRT and DS GPA score using 2 separate cut points =2.0 vs <2.0 and =2.5 vs <2.5) RESULTS A total of 126 NSCLC patients were included for analysis, with median follow up of 14.2 months. Data for DS GPA calculation were available for 86.3% of all enrolled NSCLC patients. Overall, 50.0% of patients had DS GPA score =2.0, and 23.0% of patients had DS GPA scores =2.5. The SRS and SRS WBRT groups were well balanced with regard to prognostic factors. The median survival according to receipt of WBRT was 11.3 months +WBRT) and 17.9 months WBRT) for patients with DS GPA =2.0 (favorable prognoses, P=.63; hazard ratio 0.86; 95% confidence interval 0.47 1.59) Median survival was 3.7 months +WBRT) and 6.6 months WBRT) for patients with DS GPA <2.0 patients (unfavorable prognoses, P=.85; hazard ratio 0.95; 95% confidence interval 0.56 1.62) Outcomes according to the receipt of WBRT and DS GPA remained similar utilizing DS GPA =2.5 as a cutoff for favorable prognoses. There was no interaction between the continuum of the DS GPA groups and WBRT on overall survival (P=.53) CONCLUSIONS We observed no significant differences in survival according to receipt of WBRT in favorable prognosis NSCLC patients. This study further supports the approach of SRS alone in the majority of patients with limited brain metastases.
International journal of radiation oncology, biology, physics