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9 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Meningiomas grow from the membranes covering the brain and spinal cord rather than from the brain itself. Most are slow and benign and are either watched or removed; radiotherapy or radiosurgery treats what surgery cannot reach or what grows back, and no drug has yet been approved for them.
Meningiomas arise from arachnoid cap cells and are graded 1 to 3 in WHO 2021 by mitotic count, brain invasion and specific histological patterns, with two molecular criteria that assign grade 3 regardless of appearance: homozygous CDKN2A/B deletion and TERT promoter mutation. About half of sporadic tumours carry NF2 loss with monosomy 22, and most of the rest carry mutually exclusive mutations in TRAF7, KLF4, AKT1, SMO, PIK3CA or POLR2A that cluster at the skull base (Clark and Brastianos, 2013). DNA methylation classes and integrated molecular grading (Sahm 2017, Nassiri 2021) predict recurrence better than histology alone. Radiation exposure is the only established environmental cause; progesterone and oestrogen receptors explain the female excess and the link to some progestogens.
Incidental small meningiomas are watched with MRI. Symptomatic or growing tumours are resected, with completeness graded by the Simpson scale, and complete resection of a grade 1 tumour is usually curative. Radiosurgery controls most small tumours (under about 3 cm) and is the usual choice for skull base and cavernous sinus lesions that cannot be safely removed. Fractionated radiotherapy is given after incomplete resection of grade 2 tumours and after any resection of grade 3 tumours, following the phase 2 EORTC 22042-26042 and RTOG 0539 studies; whether completely resected grade 2 tumours need radiotherapy is the question of the ROAM/EORTC 1308 and NRG BN003 randomised trials. Proton therapy is used for large skull base and re-irradiation cases.
| Setting | Approach | Guideline |
|---|---|---|
| Incidental or small asymptomatic | Observation with serial MRI; many never grow. Treatment when growth or symptoms appear. | not mapped |
| Symptomatic or growing, accessible | Surgical resection as complete as safely possible; complete resection of a grade 1 tumour is usually curative and needs no adjuvant treatment. | not mapped |
| Small, skull base or surgically inaccessible | Stereotactic radiosurgery (Gamma Knife, CyberKnife or linac) or fractionated stereotactic radiotherapy, with high long-term control rates for grade 1 tumours. | not mapped |
| Grade 2, incompletely resected, and all grade 3 | Fractionated radiotherapy after surgery (EORTC 22042-26042, RTOG 0539); proton therapy for large or re-irradiated skull base tumours; observation versus radiotherapy after complete resection of grade 2 tumours is under trial (ROAM/EORTC 1308, NRG BN003). | not mapped |
| Recurrent, no surgical or radiotherapy option | No approved drug. Bevacizumab, sunitinib or everolimus with a somatostatin analogue on phase 2 evidence; mutation-matched trials (Alliance A071401) and peptide receptor radionuclide therapy studies preferred. | not mapped |