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Validation of the modified radiosurgery-based arteriovenous malformation score in a linear accelerator radiosurgery
George K C Wong1, Michael K M Kam, Samuel K W Chiu
1Division of Neurosurgery, Department of Surgery, 4/F Clinical Science Building, Prince of Wales Hospital, The Chinese University of Hong Kong, 1 Ngan Shing Street, Shatin, New Territories, Hong Kong. georgewong@surgery.cuhk.edu.hk
Abstract:
The modified radiosurgery-based arteriovenous malformation (AVM) score (modified AVM score or Pollock-Flickinger AVM score [PFAS]) is a simplified grading system developed to predict outcome after gamma knife radiosurgery for cerebral AVM. The purpose of this study was to test the PFAS in a cohort of patients managed with linear accelerator (LINAC) radiosurgery. We analyzed 70 consecutive patients with cerebral AVM treated with LINAC radiosurgery in Hong Kong. The scores were determined by the following equation: Modified AVM score=(0.1×volume [cm(3)])+(0.02×age [years])+(0.5×location). The location values are as follows: hemispheric/corpus callosum/cerebellar=0; basal ganglia/thalamus/brainstem=1. A total of 74% of patients presented with ruptured AVM before radiosurgery. The overall obliteration rate was 86%. Five (7%) patients developed new permanent neurological deficits from delayed bleeding or radiation-induced complications. Modified AVM score correlated with the percentage of patients with AVM obliteration without new neurological deficits (≤1, 96%; 1.01-1.50, 78%; 1.51-2.00, 90%; >2, 50%; Spearman's rho 0.354, p=0.003). In conclusion, the modified AVM score is a good predictor of patient outcome after LINAC radiosurgery in our cohort. The modified AVM score can be used to guide treatment selection for cerebral AVM and stratify patients for future comparative analyses.
Insights
The modified AVM score effectively predicts outcomes for cerebral arteriovenous malformation (AVM) patients treated with linear accelerator (LINAC) radiosurgery. This scoring system aids in treatment selection and patient stratification for future research.
Area of Science:
- Neurosurgery
- Radiation Oncology
- Medical Imaging
Background:
- Cerebral arteriovenous malformations (AVMs) pose significant neurological risks.
- Predictive scoring systems are crucial for optimizing AVM treatment outcomes.
- The modified AVM score (Pollock-Flickinger AVM score [PFAS]) was initially developed for Gamma Knife radiosurgery.
Purpose of the Study:
- To validate the efficacy of the modified AVM score (PFAS) in predicting outcomes for cerebral AVM patients treated with linear accelerator (LINAC) radiosurgery.
- To assess the correlation between the modified AVM score and treatment success rates.
Main Methods:
- Analysis of 70 consecutive patients with cerebral AVM treated with LINAC radiosurgery.
- Calculation of the modified AVM score using a defined formula: Modified AVM score = (0.1 × volume [cm³]) + (0.02 × age [years]) + (0.5 × location).
- Correlation analysis between the modified AVM score and patient outcomes, including obliteration rates and neurological deficits.
Main Results:
- An overall obliteration rate of 86% was achieved.
- Five patients (7%) experienced new permanent neurological deficits.
- The modified AVM score showed a significant correlation with successful AVM obliteration without new neurological deficits (Spearman's rho = 0.354, p = 0.003).
Conclusions:
- The modified AVM score is a reliable predictor of patient outcomes following LINAC radiosurgery for cerebral AVM.
- The PFAS can guide treatment decisions for cerebral AVMs.
- The score facilitates patient stratification for comparative studies and clinical trials.
