Background
Phase III RCT. 399 patients with ≤3 brain metastases from solid tumors (excluding SCLC, lymphoma, leptomeningeal) previously treated with SRS or surgical resection. Randomized to WBRT + SRS vs SRS alone. Primary aim: assess whether adding WBRT to SRS prolongs OS vs SRS alone in limited brain metastases. Landmark trial addressing WBRT omission in limited brain metastases. (Aoyama H et al, JAMA 2006 — referred to as Lok in some pocket guides based on subsequent NCCTG data).
Interventions and follow up
Arm A: WBRT (30 Gy/10 fractions or 37.5 Gy/15 fractions) + SRS boost to each lesio
Arm B: SRS alone (dose per lesion diameter: 15–24 Gy single fraction)
Primary endpoint: OS
mFollow up: 7.4 month
Arm B: SRS alone (dose per lesion diameter: 15–24 Gy single fraction)
Primary endpoint: OS
mFollow up: 7.4 month
Results
mOS (WBRT + SRS): 7.5 months vs SRS alone 8.0 months, P=.42 — no difference
Intracranial failure at 1 yr: 47% (WBRT + SRS) vs 76% (SRS alone), P<.001
Neurologic death: 22% (WBRT + SRS) vs 19% (SRS alone), P=.17
Cognitive function (Hopkins Verbal Learning): WBRT significantly worse at 4 months
Intracranial failure at 1 yr: 47% (WBRT + SRS) vs 76% (SRS alone), P<.001
Neurologic death: 22% (WBRT + SRS) vs 19% (SRS alone), P=.17
Cognitive function (Hopkins Verbal Learning): WBRT significantly worse at 4 months
Adverse events
Main adverse events: WBRT: alopecia, fatigue, acute cognitive effects (Hopkins Verbal Learning Test decline 30% vs 8% at 4 months). SRS alone: higher intracranial relapse requiring salvage treatment.
Conclusions
Adding WBRT to SRS did not improve OS compared to SRS alone for ≤3 brain metastases despite significantly better intracranial control. WBRT caused significant neurocognitive decline. SRS alone with close MRI surveillance is the standard of care for limited brain metastases.
Key Limitations
Key Limitations: Multiple positive trials (EORTC 22952, NCCTG N0574, JROSG 99-1) all show same result — no OS benefit with WBRT + SRS. WBRT is now generally avoided in limited brain metastases except for SCLC, leptomeningeal disease, or multiple rapidly progressing metastases uncontrollable with SRS.
Clinical Context
The convergent evidence from JROSG 99-1 (Aoyama), EORTC 22952 (Kocher), and NCCTG N0574 (Brown) confirms SRS alone as standard for limited brain metastases. WBRT is reserved for SCLC, diffuse/multiple (>4) brain metastases not amenable to SRS, or leptomeningeal disease. Hippocampal-avoidance WBRT (HA-WBRT) may reduce neurocognitive toxicity when WBRT is needed.
References