jc 18.10.2012

Paul P. Huang et al.

“Long-term Outcomes After Staged-Volume Stereotactic Radiosurgery for Large Arteriovenous Malformations”

Neurosurgery 71:632–644, September 2012

David BerviniJC, ASAM

18.10.2012

PATIENTS AND METHODS

Prospective

Cases series, not randomized

Strong radiosurgery protocol

M 35y (3)-4-5M 23ml

23 ml = 23 cm3

• 2.8 cm side cube • 3.5 cm diameter sphere

LARGE?

SM (3)-4-5 -> ELOQUENT AREAS

When?

Good recovery!

Selection bias

LARGE: “radiosurgical definition”

44% embolization before radiosurgery

• Only 12 underwent FU DSA

• FU < 10y

Attrition bias

Long-term?

Statistical Analysis

KM curves

No information about comparison between curves (Cox-Mantel log-rank test? Gehan-

Breslow-Wilcoxon test? Peto modification?)

No Cox regression analysis

Statistical bias

RESULTS

TOT Occlusion rate 61%

29%

Information bias

31%, in eloquent regions!

P >> .05

Number at risk after 5yrs?

Seizure Control

10 Pts before ttt

6 stable3 transient increase

1 improved

No positive impact of treatment

Neurological deficits

5 before ttt

2 worsening (not related to heamorrhage)

No positive impact of treatment

Take away message

+Strict radiosurgery protocol

respected for 13yrs

Good economy of words

Good organization of paper

Good relevance and accuracy of bibliography (radiosurgery)

Good quality of illustrations

-Poor design

Many bias

Very poor statistical analysis and power

Distracting graphs

Debatable results

This paper does not help me to understand the indications and advantages of fractioned radiosurgery for patients presenting with

“large”, “symptomatic” AVMs.