TY - JOUR

T1 - Assessing the volume of large cerebral arteriovenous malformations

T2 - Can the ABC/2 formula reliably predict true volume?

AU - Kashanian, Alon

AU - Sparks, Hiro

AU - Kaprealian, Tania

AU - Pouratian, Nader

N1 - Publisher Copyright:
© 2019 Elsevier Ltd

PY - 2019/7

Y1 - 2019/7

N2 - Background: Outcomes of stereotactic radiosurgery in the treatment of cerebral arteriovenous malformations (AVMs)are volume-dependent. The ability to estimate AVM volume has significant value in guiding AVM management. Objective: To determine whether AVM volume measurement calculated from the ABC/2 formula is accurate compared to volume calculated by a computer-assisted planimetric method for large AVMs. Methods: Retrospective review of 42 intracranial AVMs >3 cm in diameter that underwent treatment with dose-staged hypofractionated stereotactic radiotherapy (HSRT)from 2001 to 2018. Two raters independently measured pre- and post-HSRT volumes using both the ABC/2 formula and computer-assisted planimetry in a blinded fashion. Inter-rater reliability was assessed by calculation of intra-class correlation coefficient (ICC). Absolute volumes and percent volume change following HSRT as determined using the two methods were compared using paired t-tests, linear regression, and Bland-Altman plot analyses. Results: The ICC between the 2 raters for planimetric and ABC/2 volumes was 0.859 and 0.799, respectively. ABC/2 volumes, 26.1 ± 26.6 cm3, were statistically smaller than planimetric volumes, 28.6 ± 27.1 cm3 (P =.008). Despite differences, the two methods were highly correlated (R2 = 0.904, linear regression). The percent volume change following HSRT was significantly greater with the ABC/2 method than compared to planimetry (P =.009). Conclusion: The ABC/2 and planimetric methods are reproducible for measuring cerebral AVM volumes. Although the ABC/2 method of volume estimation underestimates planimetric AVM volume, the high correlation between the two suggests utility of the ABC/2 method if one understands its limits, particularly with respect to estimating change in AVM volume after treatment.

AB - Background: Outcomes of stereotactic radiosurgery in the treatment of cerebral arteriovenous malformations (AVMs)are volume-dependent. The ability to estimate AVM volume has significant value in guiding AVM management. Objective: To determine whether AVM volume measurement calculated from the ABC/2 formula is accurate compared to volume calculated by a computer-assisted planimetric method for large AVMs. Methods: Retrospective review of 42 intracranial AVMs >3 cm in diameter that underwent treatment with dose-staged hypofractionated stereotactic radiotherapy (HSRT)from 2001 to 2018. Two raters independently measured pre- and post-HSRT volumes using both the ABC/2 formula and computer-assisted planimetry in a blinded fashion. Inter-rater reliability was assessed by calculation of intra-class correlation coefficient (ICC). Absolute volumes and percent volume change following HSRT as determined using the two methods were compared using paired t-tests, linear regression, and Bland-Altman plot analyses. Results: The ICC between the 2 raters for planimetric and ABC/2 volumes was 0.859 and 0.799, respectively. ABC/2 volumes, 26.1 ± 26.6 cm3, were statistically smaller than planimetric volumes, 28.6 ± 27.1 cm3 (P =.008). Despite differences, the two methods were highly correlated (R2 = 0.904, linear regression). The percent volume change following HSRT was significantly greater with the ABC/2 method than compared to planimetry (P =.009). Conclusion: The ABC/2 and planimetric methods are reproducible for measuring cerebral AVM volumes. Although the ABC/2 method of volume estimation underestimates planimetric AVM volume, the high correlation between the two suggests utility of the ABC/2 method if one understands its limits, particularly with respect to estimating change in AVM volume after treatment.

KW - ABC/2

KW - Cerebral arteriovenous malformations

KW - Planimetry

KW - Radiosurgery

KW - Volume

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U2 - 10.1016/j.jocn.2019.04.038

DO - 10.1016/j.jocn.2019.04.038

M3 - Article

C2 - 31064679

AN - SCOPUS:85064981465

VL - 65

SP - 1

EP - 5

JO - Journal of Clinical Neuroscience

JF - Journal of Clinical Neuroscience

SN - 0967-5868

ER -