NRG Oncology RTOG 0539 NCT00895622
ForWHO grade 1-3 meningioma, newly diagnosed or recurrent, any resection extent
TL;DR10-yr PFS 85.2% observed low-risk, 72.2% intermediate-risk at 54 Gy, 42.5% high-risk at 60 Gy.
The transferable RT read is the target: 54 Gy/30 fx for intermediate-risk and 60 Gy/30 fx for high-risk, with grade 3+ RT-attributed toxicity 9.6% and 15.1%. Recurrent grade 1 salvaged with RT reached only 67.0% 10-yr OS, worse than upfront grade 2 post-GTR at 91.0%, which argues against deferring RT in a grade 1 you expect to recur.
In newly diagnosed WHO grade 2 meningioma after GTR, this supports upfront 54 Gy while NRG BN003 and ROAM read out; it does not speak to observation in that group, since no untreated grade 2 arm was enrolled.
The transferable parameters are 54 Gy/30 fx intermediate-risk and 60 Gy/30 fx high-risk, with grade 3+ RT-attributed toxicity of 9.6% and 15.1%. Recurrent grade 1 salvaged with RT reached only 67.0% 10-yr OS vs 91.0% for upfront grade 2 post-GTR, which argues against deferring RT in a grade 1 likely to recur.
Extent of resection carried more weight than histology: STR vs GTR gave PFS HR 2.58 (1.09-6.11) and OS HR 3.38 (1.28-8.91) on multivariable analysis. Even in observed low-risk grade 1 disease, 10-yr PFS was 88.0% after GTR vs 72.7% after STR, so a Simpson-grade decision at the first operation still shows at 10 years.
10 details 4 trials watching
Multi-arm prospective phase 2 trial (NCT00895622) of risk-adapted management, not randomised: each risk group followed its own assigned strategy. 244 consented, 165 eligible and treated per protocol. Original primary endpoint was 3-yr PFS, previously reported; this is the mature analysis with data cutoff 8/15/2023 and median follow-up 12.1, 12.0 and 11.1 years across the three cohorts.
Adults ≥18 with Zubrod 0-1 and histologically confirmed unifocal WHO grade 1-3 meningioma, newly diagnosed or recurrent, any resection extent, with centrally confirmed pathology. Median age 56, 62 in the high-risk group; 65.5% female overall. Recurrent disease made up 30.8% of the intermediate and 47.2% of the high-risk cohorts.
Group 1 (grade 1 post-GTR/STR) was observed only. Group 2 (recurrent grade 1, or newly diagnosed grade 2 post-GTR) received 54 Gy in 30 fractions. Group 3 (newly diagnosed grade 2 post-STR, newly diagnosed grade 3, or recurrent grade 2/3) received 60 Gy in 30 fractions.
The gradient tracks risk assignment cleanly at 10 years, and the two Cox covariates that survive adjustment are recurrent disease and subtotal resection, both for PFS and OS. See the cohort and covariate tables above.
| Cohort | Management | 10-yr PFS | 10-yr OS | 10-yr cum. incidence progression |
|---|---|---|---|---|
| Low (grp 1, n=60) | Observation | 85.2% (75.7-94.8) | 94.1% (87.6-100) | 8.9% (3.2-18.2) |
| Intermediate (grp 2, n=52) | RT 54 Gy | 72.2% (59.2-85.1) | 84.7% (74.2-95.2) | 21.2% (10.8-33.9) |
| High (grp 3, n=53) | RT 60 Gy | 42.5% (28.7-56.3) | 51.1% (37.0-65.2) | 39.3% (25.8-52.5) |
| Covariate | PFS HR (95% CI), p | OS HR (95% CI), p |
|---|---|---|
| Recurrent vs initial | 2.5 (1.01-6.18), p=0.047 | 2.86 (1.06-7.70), p=0.038 |
| STR vs GTR | 2.58 (1.09-6.11), p=0.031 | 3.38 (1.28-8.91), p=0.014 |
Grade 3+ AEs attributed to radiotherapy occurred in 5 pts (9.6%) of the intermediate-risk and 8 pts (15.1%) of the high-risk cohorts. Newly reported late events in the intermediate group were auditory and neurologic grade 3 plus one grade 4 hemorrhage. Zubrod, MMSE and neurologic function score were stable over time.
This is the mature counterpart to the trial's own 3-yr landmark reports and now sits as the benchmark alongside the ongoing de-escalation questions in NRG BN003 (NCT03180268) and ROAM/EORTC 1308, both of which test whether grade 2 post-GTR needs RT at all. Until those read out, the 10-yr PFS 72.2% and OS 84.7% here are the reference numbers for treating that group.
Pathology was graded under the WHO criteria of the enrolment era, so some group 1 tumors would likely be reclassified today, which is the trial's own proposed explanation for the poor recurrent grade 1 outcomes. Subgroup estimates rest on very small denominators, with intervals such as 15.0% (0-42.0%) for recurrent grade 2 PFS that cannot support a practice decision on their own.
The trial settles the low-risk question (observe after GTR, 10-yr PFS 88.0%) and confirms that high-risk disease is not controlled by 60 Gy, with 10-yr PFS 42.5%. What it cannot settle is whether the intermediate-risk result reflects RT or favorable biology, since no group 2 patient went untreated.
Non-randomised risk-adapted phase 2 with mature 10+ yr follow-up; supports existing consensus (observe post-GTR grade 1, RT otherwise) rather than testing it against a control.
- Does grade 2 meningioma post-GTR need adjuvant RT at all recruiting Observation or Radiation Therapy in Treating Patients With Newly Diagnosed Grade II Meningioma That Has Been Completely Removed by Surgery Phase 3n=163 · primary completion 2027-06 · randomised RT vs observation, GTR grade II
- Whether molecular classification reassigns recurrent grade 1 tumors n=210 · primary completion 2026-03 · methylation + histone PTM signature for recurrence
- How to improve first-line treatment for high-risk meningioma recruiting Vismodegib, FAK Inhibitor GSK2256098, Capivasertib, and Abemaciclib in Treating Patients With Progressive Meningiomas Phase 2n=124 · primary completion 2027-01 · mutation-matched targeted arms, progressive tumorsactive A Trial of Increased Dose Intensity Modulated Proton Therapy (IMPT) for High-Grade Meningiomas Phase NAn=21 · primary completion 2027-08 · dose-escalated IMPT, STR grade II / grade III
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Abstract
The longer read
The value of this readout is not that it changes what anyone does with meningioma, but that it puts durable numbers on three management strategies that have been running on institutional series and consensus opinion. Meningioma is a slow disease and the field's evidence has been correspondingly short: 3-year PFS, the trial's original endpoint, is close to uninformative for a grade 1 tumor after gross total resection. Twelve years of median follow-up is the interval at which observation either holds or does not, and it holds. A 10-year PFS of 88.0% after GTR in observed low-risk patients is the number that justifies not irradiating those patients, and it should displace softer reassurances in that conversation.
The read on the intermediate-risk cohort requires more care than the headline invites. Group 2 received 54 Gy and reached 72.2% 10-year PFS and 84.7% OS, but no group 2 patient was observed, so the trial cannot say what fraction of that result is radiotherapy and what fraction is the natural history of a grade 2 meningioma that has already been completely resected. This is precisely the question NRG BN003 and ROAM/EORTC 1308 were built to answer, and until they report, these figures function as an upper reference for what treatment achieves rather than as evidence of a treatment effect. A skeptic reading the same data could argue the observed 27.8% progression rate at 10 years is compatible with a population that would have done nearly as well untreated. That argument cannot be refuted from within this trial.
Two findings should move confidence more than the cohort curves do. First, recurrence and subtotal resection each roughly doubled to tripled the hazard for both PFS and OS after adjustment, with intervals that exclude one but only barely. The direction is unsurprising; the magnitude, particularly OS HR 3.38 for STR, argues that resection extent is doing more work in this disease than a benign histology label suggests, and it is the variable a surgeon controls. Second, the recurrent grade 1 patients irradiated in group 2 reached only 67.0% OS at 10 years, worse than the upfront grade 2 patients treated identically. A grade 1 tumor that has already declared itself by recurring is not behaving like a grade 1 tumor, and the trial's own explanation, that molecular classification would reassign some of these, is the most plausible one available. Practically it means the grade on the pathology report should not be the only input into how aggressively a recurrence is managed.
The high-risk result is the honest failure. Sixty Gy after surgery produced 42.5% PFS and 51.1% OS at 10 years, and within that cohort recurrent grade 2 disease fell to 15.0% PFS. Dose was already at the conventional ceiling for this anatomy, systemic options remain absent, and nothing in the pattern here suggests incremental modification of the same approach will change the trajectory. What this cohort provides is a benchmark precise enough to power the trials that should be testing something different, which is the most useful thing a mature single-strategy cohort can do.