American Journal of Neuroradiology, Vol.34(5) : 1035~1039, 2013
American Journal of Neuroradiology
BACKGROUND AND PURPOSE: The degree of variation in retreatment decisions for residual or recurrent aneurysms among endovascular
therapists remains poorly defined. We performed a multireader study to determine what reader and patient variables contribute to
MATERIALS AND METHODS: Seven endovascular therapists (4 neuroradiologists, 3 neurosurgeons) independently reviewed 66 cases of
patients treated with endovascular coil embolization for ruptured or unruptured aneurysm. Cases were rated on a 5-point scale recommending
for whether to retreat and a recommended retreatment type. Reader agreement was assessed by intraclass correlation coefficient
and by identifying cases with a “clinically meaningful difference” (a difference in score that would result in a difference in treatment).
Variables that affect reader agreement and retreatment decisions were examined by using the Wilcoxon signed-rank test, Pearson 2 test,
and linear regression.
RESULTS: Overall interobserver variability for decision to retreat was moderate (ICC 0.50; 95% CI, 0.40 – 0.61). Clinically meaningful
differences between at least 2 readers were present in 61% of cases and were significantly more common among neuroradiologists
than neurosurgeons (P .0007). Neurosurgeons were more likely to recommend “definitely retreat” than neuroradiologists
(P .0001). Previously ruptured aneurysms, larger remnant size, and younger patients were associated with more retreat recommendations.
Interobserver variability regarding retreatment type was fair overall 0.25 (95% CI, 0.14 – 0.41) but poor for experienced
readers 0.14 (95% CI, 0 – 0.34).
CONCLUSIONS: There is a large amount of interobserver variability regarding the decision to retreat an aneurysm and the type of
retreatment. This variability must be reduced to increase consistency in these subjective outcome measurements.