Halil Özer1, Merve Yazol2, Nesrin Erdoğan2, Ömer Hakan Emmez3, Gökhan Kurt3, Ali Yusuf Öner2. 1. Department of Radiology, Gazi University Faculty of Medicine, Beşevler, 06500, Ankara, Turkey. drhalilozer@gmail.com. 2. Department of Radiology, Gazi University Faculty of Medicine, Beşevler, 06500, Ankara, Turkey. 3. Department of Neurosurgery, Gazi University Faculty of Medicine, Ankara, Turkey.
Abstract
PURPOSE: This study aimed to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate early treatment response in vestibular schwannoma (VS) patients after radiosurgery. METHODS: Twenty-four VS patients who underwent gamma knife radiosurgery were prospectively followed up for at least four years. DCE-MRI sequences, in addition to standard MRI protocol, were obtained prior to radiosurgery, at 3 and 6 months. Conventionally, treatment responses based on tumor volume changes were classified as regression or stable (RS), transient tumor enlargement (TTE), and continuous tumor enlargement (CTE). DCE-MRI parameters, such as Ktrans, Kep and Ve, were compared according to follow-up periods and between groups. The diagnostic performance was tested using receiver operating characteristic (ROC) curves. RESULTS: Changes in tumor volume were as follows at the last 48 months of follow-up: RS in 11 patients (45.8%), TTE in 10 patients (41.7%), and CTE in three patients (12.5%). The median time required to distinguish TTE from CTE using conventional MRI was 12 months (range 9-18). The Ktrans and Ve were significantly decreased in patients with RS and TTE at 3 and 6 months, but did not differ significantly in patients with CTE. There were no significant differences in Ktrans and Ve between patients with RS and TTE at 3 and 6 months. Both Ktrans and Ve demonstrated high diagnostic performance in evaluating early treatment response to radiosurgery in patients with VS. CONCLUSION: DCE-MRI may aid in the monitoring and early prediction of treatment response in patients with VS following radiosurgery.
PURPOSE: This study aimed to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate early treatment response in vestibular schwannoma (VS) patients after radiosurgery. METHODS: Twenty-four VS patients who underwent gamma knife radiosurgery were prospectively followed up for at least four years. DCE-MRI sequences, in addition to standard MRI protocol, were obtained prior to radiosurgery, at 3 and 6 months. Conventionally, treatment responses based on tumor volume changes were classified as regression or stable (RS), transient tumor enlargement (TTE), and continuous tumor enlargement (CTE). DCE-MRI parameters, such as Ktrans, Kep and Ve, were compared according to follow-up periods and between groups. The diagnostic performance was tested using receiver operating characteristic (ROC) curves. RESULTS: Changes in tumor volume were as follows at the last 48 months of follow-up: RS in 11 patients (45.8%), TTE in 10 patients (41.7%), and CTE in three patients (12.5%). The median time required to distinguish TTE from CTE using conventional MRI was 12 months (range 9-18). The Ktrans and Ve were significantly decreased in patients with RS and TTE at 3 and 6 months, but did not differ significantly in patients with CTE. There were no significant differences in Ktrans and Ve between patients with RS and TTE at 3 and 6 months. Both Ktrans and Ve demonstrated high diagnostic performance in evaluating early treatment response to radiosurgery in patients with VS. CONCLUSION: DCE-MRI may aid in the monitoring and early prediction of treatment response in patients with VS following radiosurgery.
Authors: Richard G Abramson; Lori R Arlinghaus; Adrienne N Dula; C Chad Quarles; Ashley M Stokes; Jared A Weis; Jennifer G Whisenant; Eduard Y Chekmenev; Igor Zhukov; Jason M Williams; Thomas E Yankeelov Journal: Magn Reson Imaging Clin N Am Date: 2016-02 Impact factor: 2.266
Authors: O W M Meijer; E J Weijmans; D L Knol; B J Slotman; F Barkhof; W P Vandertop; J A Castelijns Journal: AJNR Am J Neuroradiol Date: 2008-02-22 Impact factor: 3.825