Meningioma Flashcards
(33 cards)
Meningiomas are the most common primary brain tumors in adults, representing approximately 40% of all primary brain tumors with ~30,500 cases per year in the United States, 80% of which are WHO grade I.
Recurrent meningiomas are …
Recurrent meningiomas are generally managed with re-resection followed by RT when no previous RT has been administered. Unresectable meningiomas are managed with fractionated RT or SRS, depending on grade, size, and location. Similar strategies are employed in the setting of spinal meningiomas (approximately 10% of cases).
While the vast majority of meningiomas are benign, they may ultimately cause significant morbidity and mortality. Particularly in young patients …
Particularly in young patients, the likelihood and morbidity of recurrence must be weighed against the potential long-term sequelae of RT to the brain. Grade II meningiomas have an intermediate prognosis, while grade III meningiomas are aggressive with high recurrence and mortality rates.
The extent of surgical resection and grade of meningioma determine initial post surgical approach.
What is the epidemiology?
EPIDEMIOLOGY: 30,551 cases per year in the United States; approximate 1-, 5-, and 10-year survival rates are 80%, 65%, and 58%, respectively (decreased survival rate with increasing age). Incidence increases with age (especially >65).1 There is approximately a 2:1 female predominance though males are slightly more likely to have atypical or malignant meningiomas.
What are the risk factors?
RISK FACTORS: Older age, ionizing radiation, NF2, MEN1, exogenous/endogenous hormones, elevated BMI, decreased physical activity, increased height (women), uterine fibroids, and breast cancer.2,4–10 The degree to which estrogen exposure is an independent risk factor from BMI, decreased physical activity, increased height, uterine fibroids, and breast cancer is unclear.
What are the anatomy’s aspects?
ANATOMY: Arises from the arachnoid layer of the meninges between the dura mater and pia mater, commonly at sites of high density of arachnoid villi and associated arachnoid cap cells. Most frequently noted at supratentorial sites of dural reflection, such as at the cerebral convexity (~20%) and parafalcine/parasagittal (~25%), along the sphenoid wing (~20%) and skull base (resulting in decreased surgical accessibility), intraventricular and suprasellar region, and olfactory groove (~10%) and in the posterior fossa most commonly along the petrous bone (~10%).
PATHOLOGY: Classified by the WHO into three grades: WHO grade I (benign), WHO grade II (atypical, yet still benign), and WHO grade III (malignant).
Table 4.2:
Summary of WHO Grading for Meningiomas
Table 4.2:
Summary of WHO Grading for Meningiomas
Table 4.2:
Summary of WHO Grading for Meningiomas
What are the possible genetics alterations?
DNA methylation profiling and other molecular signatures are promising to better risk-stratify meningiomas.11 Relevant molecular alterations include TERT, PIK3CA, POLR2A, SMO, KLF4, AKT1, TRAF7, NF2, and SUFU.
What are the clinical symptomas?
May be asymptomatic. If symptomatic: headaches, seizure, altered cognition, focal neurologic deficit.
- *Parasagittal:** motor and/or sensory changes
- *Frontal**: personality change, avolition, executive dysfunction, disinhibition, urinary incontinence, Broca’s aphasia
- *Temporal:** memory changes, Wernicke aphasia (left), aprosody (right), olfactory symptoms including seizures
- *Cavernous sinus:** CN symptoms (nerves III, IV, V1–V2, VI pass through the cavernous sinus), decreased visual acuity, impaired extraocular motion with resultant diplopia, numbness
- *Occipital lobe:** visual field deficit
What are the clinical symptomas?
- *Cerebellopontine angle:** unilateral deafness/decreased hearing, facial numbness, facial weakness
- *Optic nerve sheath:** ipsilateral decreased visual acuity/blindness, exophthalmos, ipsilateral pupillary dilation nonreactive to direct light but with retained consensual contraction
Sphenoid wing: cranial neuropathy, seizures
Tentorium: extra-axial compression with associated occipital/parietal/cerebellar symptoms
Foramen magnum: paraparesis, urinary/anal sphincter dysfunction, tongue atrophy ± fasciculation Spinal canal: back pain, Brown-Séquard (hemispinal cord) syndrome
What are the workups?
H&P with attention to the neurologic exam, head CT, MRI brain to evaluate for a well-circumscribed, classically homogeneously enhancing extra-axial mass with a dural tail (present in more than half of meningiomas—may also be present in patients with chloroma, lymphoma, and sarcoidosis). Meningiomas are T1 isointense and CT isodense with normal brain parenchyma unless contrast is administered, underscoring the importance of IV contrast when possible. Evaluate for bone invasion and/or reactive hyperostosis. Modest perilesional edema may be present; this is more frequently encountered with rapidly enlarging atypical and/or malignant meningiomas as well as convexity or parasagittal meningiomas. Extensive perilesional edema is a relative contraindication to SRS as patients may have considerable posttreatment edema following treatment of convexity meningiomas
What are the prognostic factors?
Poorer prognosis with increasing grade, decreasing extent of resection, proliferative index (Ki-67) >1%, brain invasion, age <45, chromosomal abnormalities involving 14 and 22, aggressive clinical behavior, p53 overexpression.
What is the natural history?
Approximately 1 to 2 mm of growth annually for grade I meningiomas. Most failures occur locally, and local progression can further aggravate associated neurologic symptoms. Marginal failure around the meninges is possible, particularly with high-grade meningioma.
What are the treatment paradigm?
Observation: may be appropriate for incidentally discovered small, asymptomatic meningiomas. Observation is also appropriate for WHO grade I tumors following GTR and may be considered following STR as well. Surveillance with MRI is recommended annually for patients with WHO grade I meningiomas undergoing observation to assess need for treatment.
Surgery: Standard is maximal safe surgical resection. Often requires craniotomy, but for sphenoid wing/skull base lesions, endoscopic surgery may be indicated. Simpson grade correlates with local failure (Table 4.4). Postoperative brain MRI should be obtained within 48 hours of surgery.
What are the treatment paradigm?
What is the chemotherapy?
No primary role for CHT. Although medical therapy is nonstandard, 2020 NCCN guidelines suggest patients with radiographic progression may benefit from bevacizumab to prevent rapid neurologic deterioration.
What is the radiation suggestion?
Dose: WHO grade I meningiomas generally are treated to 50.4 Gy/28 fx or 54 Gy/30 fx. WHO grade II meningiomas are treated to 59.4 Gy/33 fx or 60 Gy/30 fx. WHO grade III meningiomas are treated to 60–66 Gy/30–33 fx. See RTOG 0539 for common dosing strategy. SRS dose, when feasible, is 12 to 14 Gy for grade I tumors. When surrounding tissues allow, 16 Gy for grade II tumors may be considered as well as RTOG 9005 dosing for grade III tumors (18–24 Gy). Brachytherapy is utilized at select institutions for multiply recurrent meningiomas
Do incidentally discovered meningiomas require aggressive intervention?
Incidentally appreciated meningiomas may not require additional intervention. In at least one study, more than half of patients’ meningiomas demonstrated no growth at 5 years. These patients may be followed with imaging at 3 to 6 months and then annually thereafter if no growth is appreciated.
What is the optimal first-line management in the treatment of meningiomas?
Maximal safe surgical resection provides the greatest opportunity for minimizing recurrence rates. The extent of resection is graded according to the Simpson grading system, which was the foundational study in meningioma.
What is the optimal first-line management in the treatment of meningiomas?
Mayo Clinic (Mayo Clin Proc 1998, PMID 9787740): RR of 581 patients treated with initial resection. GTR in 80%. The 5- and 10-year PFS was 88% and 75% for GTR but only 61% and 39% for less than GTR. Perioperative mortality was 1.6%. A matched cohort analysis suggested nontrivial increase in morbidity and mortality from meningioma and/or treatment. Many of the risk factors for recurrence we use today were noted in this study. Comment: Used an older data set. Surgical techniques, radiographic evaluation, and perioperative care may have improved since that time.
What is the role of RT in the management of WHO grade I meningiomas?
GTR (Simpson 1–3) is generally considered definitive, and patients may be followed with surveillance imaging. However, with longer follow-up, recurrence rates as high as 20%, 40%, and 60% have been reported at 5, 10, and 15 years, likely reflecting modern imaging capabilities.16,25–27 RT is typically reserved for salvage for these patients. For those with STR (Simpson 4–5), recurrence rates of 40% at 5 years and 60% at 10 years can be reduced to those of GTR (approximately halved) with adjuvant RT doses >50.4 Gy
What is the role of RT in the management of WHO grade II meningiomas?
Adjuvant RT is generally recommended after GTR and strongly recommended after STR. Adjuvant RT after GTR of a WHO grade II meningioma is 54 Gy per RTOG 0539. After STR of a WHO grade II, adjuvant RT to 59.4 Gy/33 fx or 60 Gy/30 fx is recommended to minimize risk of LR based on multiple retrospective series.30–34 Without RT, LR rates of up to 60% at 5 years and CSS of only 70% at 10 years have been observed.25,35 Following GTR (Simpson 1–2), 5-year PFS is roughly doubled, from approximately 40% to 80% with adjuvant RT.31,36 Following STR, adjuvant RT is strongly recommended due to high recurrence rates.
