Adjuvant whole-brain radiotherapy versus observation after radiosurgery or surgical resection of 1–3 cerebral metastases: Results of the EORTC 22952–26001 study

Abstract

2008 Background: The EORTC Radiotherapy and Brain Tumor Groups conducted a phase III trial to define the role of adjuvant whole brain irradiation (WBRT) after local treatment (surgery or radiosurgery) for brain metastases. It was hypothetized that WBRT would increase the duration of functional independence by reducing the number of intracranial relapses. Methods: Pts eligible for radiosurgery (RS) had 1–3 metastases of solid tumors (SCLC excluded) ≤ 3.0 cm in diameter (≤ 2.5 cm for 2–3 lesions). In case of surgery (S), a complete resection was mandatory. Only pts with no or stable systemic disease or with asymptomatic synchronous primary tumors, and with WHO PS 0–2 were allowed. Pts were randomized for adjuvant WBRT or observation (OBS). Primary endpoint was survival with functional independence measured by the time to WHO PS deterioration to > 3. Analysis is by intent-to-treat (Logrank, two-sided α = 0.05). Results: From 1996–2007, 359 pts were recruited. 160 surgical pts had resection of one (96%) or two (4%) metastases, and 185 (of 199 scheduled pts) had RS (marginal dose 20Gy, target dose 25Gy) of one (67%), two (23%), or three (10%) lesions. Adjuvant whole brain irradiation (30Gy/10 fractions) was given to 166/180 pts. (92%) randomized for WBRT and to 4/179 pts (2%) in the OBS arm. Median time to WHO PS > 3 was 9.8 months (95% CI 8.0 - 11.7) in the OBS arm and 9.8 months (95% CI 7.8 - 12.6) in the WBRT arm (p > 0.5). It was only significantly influenced by initial WHO PS and initial systemic disease status (p < 0.01). Overall survival was 10.9 months (95% CI 9.2 - 14.6) in both arms (p > 0.5). Cumulative incidence of intracranial progression at 6 and 24 months was 39.7% (95% CI 32.5 - 46.8) and 54.0% (95% CI 46.7 - 61.3) of the OBS pts, but only 15.2% (95% CI 9.9 - 20.5) and 31.4% (95% CI 24.5 - 38.2) of the WBRT pts (p < 0.0001). Intracranial progression was a cause of the death in 77/179 pts (43%) of the OBS group and in only 45/180 pts (25%) of the WBRT group. Conclusions: After radiosurgery or surgery of 1–3 brain metastases, adjuvant WBRT reduces the frequency of intracranial relapses and neurologic deaths but fails to prolong the time period of functional independence and overall survial time. Updated results will be presented at the Meeting. No significant financial relationships to disclose.