CNS
Resected grade 2 meningioma finally gets randomised data on the adjuvant RT vs observation question.
ROAM/EORTC-1308
ForNewly diagnosed WHO grade 2 meningioma, Simpson I–III resection, PS ≤2
HR 0.51
95% CI 0.27–0.97, p=0.0396
TL;DRDFS HR 0.51 (95% CI 0.27–0.97), 5-yr DFS 79.9% vs 64.3% with adjuvant 60 Gy/30 fx vs observation after complete resection of atypical meningioma.
Target volumes were GTV plus 5–10 mm CTV and 3–5 mm PTV, wider than current guidance allows, and DFS counted out-of-field and new meningiomas as failures, so HR 0.51 may understate the in-field effect. Patterns-of-failure data are pending. After this trial the open RT question is margin reduction more than whether to treat.
In newly diagnosed WHO grade 2 atypical meningioma after surgeon-assessed Simpson I–III resection, this supports discussing adjuvant fractionated RT over observation; it does not address subtotal resection, recurrent disease, NF2, or multiple meningiomas.
Margins were GTV plus 5–10 mm CTV and 3–5 mm PTV, wider than current guidance, and DFS included out-of-field failures, so HR 0.51 may understate in-field benefit. The next RT question is margin reduction, pending the patterns-of-failure analysis.
Eligibility rested on surgeon-assessed Simpson I–III resection without early postoperative MRI, and 70% of observed tumours did not recur by about 5 years. Re-resectable locations such as right frontal convexity are named as a reason to defer RT, keeping surveillance with salvage surgery a defensible path.
10 details
International, multicentre, open-label phase 3 RCT, 1:1, stratified by UK vs non-UK. N=157 randomised between 2016 and 2021 at 58 hospitals in 11 countries. Median follow-up 64 months.
Age ≥16 with histologically confirmed, newly diagnosed atypical meningioma after surgeon-assessed gross total resection (Simpson I–III), WHO PS ≤2, able to start RT within 12 weeks. Excluded NF2, multiple or radiation-induced meningiomas, optic nerve sheath tumours, prior intracranial tumours.
IMRT 60 Gy in 30 fractions over 6 weeks, median 2.50 months from surgery to start. CTV was an isotropic 5–10 mm GTV expansion respecting anatomy, then 3–5 mm to PTV, with prospective central plan review.
Primary: DFS, from surgery to MRI-confirmed recurrence or death from any cause, ITT. Secondary: HRQoL, neurocognition (UK/Ireland only), time to second-line treatment, OS, cost-effectiveness.
The primary endpoint was met (see table). The absolute 5-yr DFS gain of 15.6 pp has a lower CI bound of 0.6, and there was no OS difference.
| Endpoint | RT (n=78) | Observation (n=79) | Effect |
|---|---|---|---|
| DFS (1° EP) | n/a | n/a | HR 0.51 (95% CI 0.27–0.97), p=0.0396 |
| 5-yr DFS | 79.9% (67.6–87.9) | 64.3% (51.9–74.2) | Abs diff 15.6 pp (0.6–30.5) |
| Meningioma recurrence | 11 (14%) | 24 (30%) | n/a |
| Deaths | 7 (9%) | 6 (8%) | 5-yr OS OR 0.91 (0.27–3.05) |
| 2nd-line treatment for recurrence | 8 (10%) | 16 (20%) | n/a |
Early and late RT-related AEs were all grade 1–2, with no grade 3+ events in the discussion's accounting. Serious RT-related events: 5 (8%) of 66, including one optic neuritis with the optic apparatus dose at constraint limits. No between-arm difference in HRQoL or neurocognition among evaluable pts.
Before this trial the evidence was single-institution retrospective series with conflicting results, plus two non-randomised phase 2 trials: 60 Gy/30 fx in 56 pts (3-yr PFS 88.7%) and 54 Gy/30 fx in 36 pts (3-yr PFS 93.8%). This is the first randomised comparison against observation.
No central pathology review: 5 pts would now be reclassified grade 3. There was no early postoperative MRI within 72 h. HRQoL completion fell to 38% at 5 years and about 45% of neurocognitive data were missing by 24 months, so the null toxicity-of-function read is weak.
Under observation, 70% of meningiomas did not recur by about 5 years, so deferral stays reasonable for older or comorbid pts, lesions amenable to re-resection, or large target volumes. Methylation class was prognostic but did not erase the RT benefit in post-hoc analysis.
CONSORT flow
First randomised evidence, primary endpoint met, but 41 of 46 planned events, upper CI 0.97, open-label local read, as-treated HR crossed 1. Supports an existing guideline-listed option.
- Can modern IMRT/IGRT margins shrink the CTV without losing control?
- Does methylation class identify pts who can safely defer RT?
- In-field vs out-of-field recurrence pattern after adjuvant RT