Calculating the tumor volume of acoustic neuromas: Comparison of ABC/2 formula with planimetry method

Objective: The ABC/2 equation is commonly applied to measure the volume of intracranial hematoma. However, the precision of ABC/2 equation in estimating the tumor volume of acoustic neuromas is less addressed. The study is to evaluate the accuracy of the ABC/2 formula by comparing with planimetry method for estimating the tumor volumes. Methods: Thirty-two patients diagnosed with acoustic neuroma received contrast-enhanced magnetic resonance imaging of brain were recruited. The volume was calculated by the ABC/2 equation and planimetry method (defined as exact volume) at the same time. The 32 patients were divided into three groups by tumor volume to avoid volume-dependent overestimation (<3 ml, 3-6 ml and >6 ml). Results: The tumor volume by ABC/2 method was highly correlated to that calculated by planimetry method using linear regression analysis (R-2 = 0.985). Pearson correlation coefficient (r = 0.993, p < 0.001) demonstrates nearly perfect association between two methods. Conclusions: The ABC/2 formula is an easy method in estimating the tumor volume of acoustic neuromas that is not inferior to planimetry method. (C) 2013 Elsevier B.V. All rights reserved.