Background
Phase III, randomized, multicenter Japanese trial (JROSG 99-1). 132 patients with 1–4 brain metastases (each <3 cm diameter) randomized to SRS + WBRT vs SRS alone. Enrolled Oct 1999–Dec 2003 at 11 Japanese hospitals. Primary endpoint: overall survival. First major RCT to directly test whether WBRT added to SRS improved OS.
Interventions and follow up
Arm A: SRS + WBRT (WBRT dose 30 Gy in 10 fractions)
Arm B: SRS alone
Primary endpoint: Overall survival
mFollow up: Median ~8 month
Arm B: SRS alone
Primary endpoint: Overall survival
mFollow up: Median ~8 month
Results
OS: 7.5 vs 8.0 months (SRS+WBRT vs SRS alone), P=.42 — no difference
12-month brain tumor recurrence: 46.8% (SRS+WBRT) vs 76.4% (SRS alone), P<.001
Salvage brain treatment required: 10 vs 29 patients, P<.001
Neurologic cause of death: 22.8% vs 19.3%, P=.64 — no difference
12-month brain tumor recurrence: 46.8% (SRS+WBRT) vs 76.4% (SRS alone), P<.001
Salvage brain treatment required: 10 vs 29 patients, P<.001
Neurologic cause of death: 22.8% vs 19.3%, P=.64 — no difference
Adverse events
Main adverse events: No significant difference in radiation toxicity or functional preservation. WBRT-associated acute toxicities (fatigue, alopecia) present but not quantified separately. No formal neurocognitive assessment (key limitation).
Conclusions
Adding WBRT to SRS did not improve survival for patients with 1–4 brain metastases. However, WBRT significantly improved intracranial control and reduced need for salvage treatment. This established that SRS alone is a valid alternative to WBRT+SRS for patients with limited BM, accepting a higher rate of intracranial relapse requiring salvage.
Key Limitations
Key Limitations: Trial was likely underpowered (N=132) to detect a clinically meaningful OS difference if one existed. No formal neurocognitive testing — the major concern with WBRT (cognitive harm) was not captured. The trial was conducted in a Japanese population with different systemic treatment practices. Patients who received SRS alone had more salvage treatments, suggesting that without close follow-up and MRI monitoring, outcomes would have been worse.
Clinical Context
JROSG 99-1 was the first trial to demonstrate that omitting WBRT after SRS does not reduce OS, catalyzing the shift toward SRS-only strategies. Subsequent trials (Chang 2009, N0574 2016) added the neurocognitive rationale for omitting WBRT. Current ASCO/ASTRO/NCCN guidelines support SRS alone for 1–4 BM in patients with good prognosis, deferring WBRT. The trade-off is higher intracranial relapse, manageable with frequent MRI surveillance.
References
References: Aoyama H et al, JAMA 2006 (JROSG 99-1)