Treatment/Prognosis Flashcards
What are the Tx paradigms for meningiomas?
Meningioma Tx paradigms:
If incidental/asymptomatic: observation
If grade I and symptomatic/progressive: Sg + RT (if STR)
If grade II (high risk) or III: Sg + RT
For which types of meningioma is RT the primary Tx modality?
Optic nerve sheath and cavernous sinus (inaccessible regions)
When should observation be considered?
Observation should be considered with incidental/asymptomatic and stable lesions. Consider Sg for large (≥30 mm) lesions, if accessible.
When is RT utilized after Sg for meningiomas?
RT should be utilized after Sg if there is recurrent Dz or STR or if there is anaplastic histology or brain invasion.
What is the avg time to recurrence after Sg for meningiomas?
4 yrs is the avg time to recurrence after Sg.
What are the 10-yr recurrence rates with Sg alone after either GTR or STR?
10-yr recurrence rates with Sg alone are ∼10% after GTR and 60% after STR.
Is there a benefit to upfront RT after STR for grade I meningioma?
This is controversial (upfront control rates are considered equivalent to salvage rates). RTOG 0539 showed RT benefit for WHO II (post-STR) and all WHO III tumors (Rogers L et al., NeuroOncol 2017) and may address this question in its low-risk cohort.
What are the RT doses employed for meningiomas?
RT doses are 45–54 Gy for benign and 60 Gy for malignant tumors (CTV = GTV + 1–2 cm).
Is there any RT dose–response data for meningiomas?
Yes. Goldsmith BJ et al. showed improved PFS with doses >52 Gy. (J Neurosurg 1994)
What are typical SRS doses used for meningiomas?
Typical SRS doses range from 12–16 Gy to 50% IDL at the tumor margin (depending on location/size).
What is the 5-yr LC rate for meningiomas after SRS?
The 5-yr LC rate is ∼95% for grade I tumors. For grades II–III, it is 68% and 0%, respectively. (Stafford SL et al., Neurosurgery 2001)
What poor prognostic factors have been identified in pts receiving SRS for meningiomas?
Male sex, previous Sg, tumors located in parasagittal/falx/convexity regions (Pollock BE et al., Neurosurgery 2012)
Should the dural tail be covered in the RT field?
In general, no; however this is controversial. Some studies have shown improved 5-yr DFS when the dural tail was included in SRS Rx isodose. (DiBiase SJ et al., IJROBP 2004)
