Kashanian Alon, Sparks Hiro, Kaprealian Tania, Pouratian Nader
Department of Neurosurgery, David Geffen School of Medicine at UCLA (University of California, Los Angeles), 300 UCLA Stein Plaza, Suite 420, Los Angeles, CA, USA.
Department of Radiation Oncology, David Geffen School of Medicine at UCLA (University of California, Los Angeles), 200 UCLA Medical Plaza, Suite B265, Los Angeles, CA, USA.
J Clin Neurosci. 2019 Jul;65:1-5. doi: 10.1016/j.jocn.2019.04.038. Epub 2019 May 4.
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.
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.
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.
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 cm, were statistically smaller than planimetric volumes, 28.6 ± 27.1 cm (P = .008). Despite differences, the two methods were highly correlated (R = 0.904, linear regression). The percent volume change following HSRT was significantly greater with the ABC/2 method than compared to planimetry (P = .009).
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.
立体定向放射外科治疗脑动静脉畸形（AVM）的疗效取决于体积。估计AVM体积的能力在指导AVM治疗管理方面具有重要价值。
确定对于大型AVM，由ABC/2公式计算得出的AVM体积测量值与通过计算机辅助平面测量法计算得出的体积相比是否准确。
回顾性分析2001年至2018年期间接受剂量分割立体定向放射治疗（HSRT）的42例直径>3 cm的颅内AVM。两名评估者以盲法分别使用ABC/2公式和计算机辅助平面测量法独立测量HSRT前后的体积。通过计算组内相关系数（ICC）评估评估者间的可靠性。使用配对t检验、线性回归和Bland-Altman图分析比较两种方法确定的HSRT后绝对体积和体积变化百分比。
两名评估者对于平面测量体积和ABC/2体积的ICC分别为0.859和0.799。ABC/2体积为26.1±26.6 cm，在统计学上小于平面测量体积28.6±27.1 cm（P = 0.008）。尽管存在差异，但两种方法高度相关（R = 0.904，线性回归）。与平面测量法相比，ABC/2法HSRT后的体积变化百分比显著更大（P = 0.009）。
ABC/2法和平面测量法在测量脑AVM体积方面具有可重复性。虽然ABC/2体积估计法低估了平面测量的AVM体积，但两者之间的高度相关性表明，如果了解其局限性，特别是在估计治疗后AVM体积变化方面，ABC/2法具有实用性。
