Meningioma

Epidemiology

Overall incidence ~ 2/100,000

Most common primary brain tumor

Risk factors
Age (most commonly dx'ed in 50's and 60's)
Females
NF type 2
Breast cancer

Prior cranial radiation: Israeli tinea capitis study (PMID 3173432) of 10,000 children who received xrt for tinea capitis (doesn't that sound so much classier than ringworm). Results below:

Type of cancer	Relative risk
Thyroid cancer	20
Meningioma	4.6
Malignant glioma	1.98

Buzzwords: Whorls, Psammoma bodies

Receptor profile: PR+ in 80%; PDGF; dopamine

WHO grading system: features associated with increased malignancy include loss of architecture, increased cellularity, nuclear pleomorphism, mitotic figures, necrosis

WHO Grade	Alias	5-year recurrence %
WHO Grade 1	Benign	3%
WHO Grade 2	Atypical	38%
WHO Grade 3	Malignant	78%

Imaging

Bright, homogeneous enhancement (T1 MRI + gadolinium)

Dural tail

Possible calcifications

Difficult to correlate imaging with behavior; edema does not --> aggressiveness

Surgery

10-year LC after surgery (PMID 3403313): Complete excision 77%, subtotal resection 18%, subtotal resection + RT 82%

Simpson classification

Class	Extent of resection	Recurrence rate
1	All tumor and dural attachments	9%
2	GTR with dural cautery	19%
3	Subtotal	40%
4	Decompression only	N/A
5	Biopsy only	N/A

SRS

Contraindications: large tumor (>3.5cm), optic apparatus dose > 8Gy, extensive brainstem compression, elderly and asymptomatic patient (can just observe)

SRS for meningioma (PMID 18300891): Pitt has the definitive series, 972 patients

Rx dose: 14Gy to 50% line (at tumor margin)

Control rates: Grade 1 93%, Grade 2 50%, Grade 3 17%

Tumors that did not undergo biopsy: 97%

Optic nerve injury from SRS (PMID 12654424): 8gy 15Gy 75%

Fractionated RT: use in large tumors, compression of brain stem or near optic structures

Grade 1 dose: 54Gy

Grades 2-3: 60Gy

Further reading: Intro section to current RTOG phase II protocol 0539