Treatment/Prognosis

Question 1

What is the Tx paradigm for primary SC tumors?

Answer 1

Primary SC tumor Tx paradigm: max resection +/– RT pending grade, extent of resection and progression of Dz or definitive RT alone

Question 2

What are the 2 main advantages of upfront surgical resection?

Answer 2

Histologic confirmation and decompression of the cord

Question 3

After GTR, which meningiomas—spinal or intracranial—have higher rates of recurrence?

Answer 3

Intracranial meningiomas have a 10%–20% recurrence rate, while spinal meningiomas have ∼5% recurrence rate.

Question 4

What is the most important predictor of recurrence for meningiomas/ependymomas?

Answer 4

Extent of resection. There are few recurrences after GTR.

Question 5

In what % of SC meningioma/ependymoma pts is GTR achievable?

Answer 5

> 90% of pts. (Retrospective series: Gezen F et al., Spine 1976; Peker S et al., J Neurosurg Sci 2005)

Question 6

In what proportion of SC astrocytoma pts is GTR possible?

Answer 6

<15% of pts, d/t infiltrative nature of glioma (Raco et al., Neurosurg 2005)

Question 7

Why is RT controversial for most SC tumors, even after STR?

Answer 7

Many SC tumors are indolent (slow growing), and there is potential for SC toxicity with RT.

Question 8

What RT options are available after STR for ependymoma/meningioma?

Answer 8

Involved-field EBRT to a dose of 45–50 Gy. STR meningioma can often be observed with EBRT or SRS reserved for tumor regrowth.

Question 9

Does WHO grade I or grade II spinal ependymoma carry a worse prognosis?

Answer 9

WHO grade I (Tarapore PE et al., Neurosurg 2013)

Question 10

What Tx options are available for SC astrocytomas?

Answer 10

Low grade: observe after GTR/consider 45–50.4 Gy after STR or definite progression

High grade: 45–54 Gy

Question 11

What retrospective series support RT in pediatric pts with low-grade SC astrocytomas?

Answer 11

JHH: After surgical resection, 12 of 29 pts rcvd RT to a median dose of 47.5 Gy. Acute RT toxicity was low grade, and long-term side effects were uncommon and manageable at median f/u of ∼4.3 Gy. In 7 of 8 pts with low-grade tumors who rcvd adj or salvage RT, there was no Dz progression or recurrence. (Guss ZD et al., IJROBP 2013)

Question 12

What retrospective studies support use of RT in SC astrocytomas?

Answer 12

Postop RT improved survival in more aggressive infiltrative astrocytoma. Use of RT in pilocytic astrocytoma may be overtreatment. (Minhehan, IJROBP 2009)
PMH: PFS was significantly influenced by RT in low- and intermediate-grade tumors; however, the RT group had fewer complete resections as c/w the Sg alone group (13% vs. 53%; p = 0.01). (Rodrigues GB et al., IJROBP 2000; Abdel-Wahab M et al., IJROBP 2006)

Question 13

What data support the RT dose–response for SC ependymomas?

Answer 13

Garcia DM: <40 Gy, 23% OS; >40 Gy, 83% OS (IJROBP 1985)

Mayo Clinic data: 35% LF for <50 Gy vs. 20% for >50 Gy (Shaw EG et al., IJROBP 1986)

Question 14

For what type of SC tumor has adj RT been shown to be beneficial, regardless of extent of resection?

Answer 14

Adj RT has been shown to be beneficial with myxopapillary ependymoma.

MDACC data: +/– 50.4 Gy RT 10-yr LC GTR/STR (55%/0%) vs. GTR + RT/STR + RT (90%/67%), all SS (Akyurek S et al., J Neurooncol 2006)

Question 15

What RT schedule is often used for high-grade ependymomas with CSF spread?

Answer 15

CSI to 36 Gy + boost to 50.4–54 Gy gross Dz

Question 16

What anatomic region needs to be covered with RT in caudal ependymomas?

Answer 16

The thecal sac down to S2–3 needs to be covered.

Question 17

What are the typical sup–inf RT margins for SC tumors?

Answer 17

The typical sup–inf margin required for SC tumors is 3–5 cm (1 vertebral body above and below tumor mass).