EORTC 22042-26042

Background

Phase II, prospective, single-arm trial (EORTC 22042-26042), N=56 evaluable at 16 European centers. Newly diagnosed WHO grade II (atypical) meningioma after gross-total resection (GTR; Simpson 1–3). All received adjuvant fractionated RT within 12 weeks of surgery. Key inclusion: MRI-confirmed GTR, central-review WHO grade II histology, KPS ≥70.

Interventions and follow up

Treatment: Adjuvant fractionated photon RT 60 Gy in 30 fractions within 12 weeks of GTR (Simpson 1–3) of newly diagnosed WHO grade II meningioma
Primary endpoint: 5-year PFS
mFollow up: Median 58.4 months

Results

5-yr PFS: 87.9% (95% CI 76.9–93.9%)
5-yr OS: 96.1%
Local failure at 5 years: 8.9%

Adverse events

Acute grade ≥3 toxicity: 33.9% (predominantly fatigue)
Late grade ≥3 toxicity: 18.1% (fatigue, neurocognitive effects, visual disturbance)
Grade 3 cognitive disorder: 3.6%
Radiation necrosis: 1 patient; no grade 4–5 late RT-related toxicity

Conclusions

Adjuvant RT to 60 Gy after GTR of WHO grade II meningioma achieved 5-year PFS of 87.9%, substantially exceeding historical surgery-alone rates of ~60–75%, supporting routine adjuvant RT even after complete resection of atypical meningioma.

Key Limitations

Single-arm with no concurrent observation control — benefit inferred against historical rates. Small sample (N=56). No molecular stratification. The competing question of adjuvant RT vs observation after GTR of grade II meningioma is being tested in the randomized ROAM/EORTC-1308 trial.

Clinical Context

Key prospective evidence for adjuvant RT after GTR of atypical (grade II) meningioma. Complements RTOG 0539 intermediate-risk data. Whether to irradiate vs observe completely resected grade II meningioma remains debated pending randomized ROAM/EORTC-1308 results.

References