CNS
Two reads on the same postop meningioma dose question: RTOG 0539's mature 10-yr risk-stratified benchmark, and a retrospective IPD meta-analysis arguing 60 Gy is too low for high-risk disease, at the cost of doubled radionecrosis and no OS gain.
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.
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📚 Sources · 📄 1 paper
Abstract
FIRESTORM
ForHigh-risk meningioma (WHO gr 2 post-STR, recurrent gr 2, any gr 3), postop RT
HR 0.40
95% CI 0.24-0.69, P = .001 (MVA); IPTW HR 0.45 (0.24-0.83)
TL;DR5-yr PFS 65.8% vs 38.8% with dose-escalated postop RT (BED ≥79.2 Gy) in high-risk meningioma; MVA HR 0.40.
The benefit survives the obvious confounders: excluding the 35 single-fraction SRS cases from SD-RT, DE-RT still gave 5-yr PFS 65.8% vs 41.7% (HR 0.56, 0.36-0.86), and photon-alone escalation matched carbon on PFS (68.3% vs 61.1%) with 0% grade ≥3 radionecrosis. That makes 66-70 Gy conventionally fractionated photons the practical escalation route, not particle referral.
In a subtotally resected WHO grade 2 or any grade 3 meningioma being planned for postoperative RT, this supports considering escalation beyond 60 Gy/30 fx rather than defaulting to it; it does not speak to gross-totally resected grade 1 disease.
Photon-alone escalation to 70 Gy/35 fx or 66 Gy/33 fx matched carbon on 5-yr PFS (68.3% vs 61.1%) with zero grade ≥3 radionecrosis, versus 9.1% in the carbon subgroup. Boost PTV margins were 0.5 to 2 mm off cavity and residual tumor. That makes escalation a standard photon department decision, not a particle referral.
14 details
Individual patient-level meta-analysis pooling 248 patients from 7 international institutions, all retrospective except one prospective trial. Median follow-up 67.1 months (range 2.13-178). PFS was the primary outcome, analyzed by Kaplan-Meier, Cox MVA, and IPTW propensity weighting.
High-risk meningioma per RTOG 0539: newly diagnosed WHO grade 2 after STR/biopsy, any recurrent grade 2, or any grade 3. 188 (75.8%) were grade 2, 103 (41.5%) recurrent, and 182 (75.2%) had Simpson grade 4/STR. Median age 60; 55 (22.2%) had prior RT.
DE-RT was defined by biologically effective dose ≥79.2 Gy (equivalent to 66 Gy in 33 fractions) or receipt of a carbon-ion boost; anything below that threshold counted as SD-RT. Photon DE-RT used a sequential or simultaneous integrated boost with a 0.5 to 2 mm PTV margin, versus 1-2 cm CTV margins in the SD-RT arm. Carbon DE-RT boosted 16 Gy/8 fx after 50 Gy/25 fx photons with a 6 mm CTV margin.
Whole-cohort 3- and 5-yr PFS were 62.8% and 45.0%. DE-RT improved 3-yr (86.4% vs 55.6%) and 5-yr PFS (65.8% vs 38.8%), P = .0022, holding on stratified Cox by grade (HR 0.40, 0.22-0.73) and after IPTW (3-yr 84.7% vs 55.8%). OS was not improved on MVA or IPTW.
| Subgroup | 3-yr PFS DE-RT vs SD-RT | 5-yr PFS DE-RT vs SD-RT | MVA HR (95% CI) | P |
|---|---|---|---|---|
| Simpson 1-3 | 87.5% vs 55.9% | 70.0% vs 40.0% | 0.31 (0.08-1.14) | .08 |
| Simpson 4-5 | 86.3% vs 55.4% | 63.3% vs 38.4% | 0.55 (0.36-0.84) | .006 |
| Cohort | Any-grade RN | Grade ≥3 RN |
|---|---|---|
| DE-RT overall | 20 of 59 (33.9%) | 3 of 59 (5.1%) |
| DE-RT mixed carbon/photon | 15 of 33 (45%) | 3 of 33 (9.1%) |
| DE-RT photon-alone | 5 of 26 (19.2%) | 0% |
| SD-RT | 25 of 189 (13.2%) | 6 of 189 (3.2%) |
Any-grade radionecrosis was 33.9% with DE-RT vs 13.2% with SD-RT (P = .001), but grade ≥3 RN did not differ (5.1% vs 3.2%, P = .47). All 3 grade ≥3 events in the DE-RT arm occurred in the mixed carbon-photon cohort; the photon-alone DE-RT cohort had none, and its any-grade RN rate was not significantly higher than SD-RT (P = .41). One grade 5 event occurred in each arm.
Published series anchored on RTOG 0539 report 5-yr PFS of roughly 40% to 60% with 60 Gy/30 fx, which is what the SD-RT arm reproduces (45.0% overall). The escalation signal draws on MARCIE (carbon boost) and the Zeng et al. photon series, both contributors to this pool, so the comparison is partly internal rather than independent.
DE-RT was delivered at only 2 of 7 institutions, one carbon-only and one photon-only, so treatment arm is nearly collinear with center, and unmeasured practice differences (DOTATATE PET planning, response assessment, supportive care) travel with it. Molecular classification was unavailable, and P values were not adjusted for multiple testing across the subgroup analyses.
The Simpson 1-3 subgroup showed absolute separation as large as Simpson 4-5 (5-yr PFS 70.0% vs 40.0%) without reaching significance (P = .08 on MVA), which the authors attribute to a smaller GTR subset and fewer events rather than an absent effect. Whether escalation belongs in fully resected disease is the open question, and the PFS-only benefit means the case rests on avoiding local progression and its neurologic morbidity, not on survival.
Retrospective IPD pooling, DE-RT confined to 2 centers, no randomization; IPTW cannot remove selection. Direction consistent across every sensitivity analysis, but prospective randomization still needed.
- Benefit of dose escalation after gross total resection
- Whether molecular subgroups predict DE-RT benefit
- Prospective randomized confirmation of the PFS signal