Article
Prospective double blinded study for the preoperative prediction of the consistency of meningiomas by the calculation of the fractional anisotropy value in MRI
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Published: | September 16, 2010 |
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Objective: The preoperative planning of meningiomas is influenced by depth, localization, size and consistency of the tumor. Some meningiomas could be resected on bloc; some by coagulation und suction and others needed the use of a CUSA. We evaluated in a prospective double blinded study the prediction of meningioma consistency by measuring the fractional anisotropy (FA) value based on a diffusion tensor (DT) sequence in magnetic resonance imaging (MRI).
Methods: All patients got a preoperative MRI with a DT sequence. The FA value was calculated on the DT image by a radiologist. The consistency of the meningioma was defined intraoperative by the neurosurgeon and postoperative by the pathologist. The quantity of resection (mg/min) was measured by using the CUSA in vitro after the tumor resection.
Results: Since 2008 we included 35 patients into this ongoing prospective double blinded study. In all but 2 cases we found an agreement in defining the consistency of meningiomas (soft, scirrhous, hard) by the neurosurgeon and the pathologist (p=0,001). The analysis of the correlation between in vitro and in vivo definition of the tumor consistency and quantified resection (CUSA) with the FA value were highly significant (p=0,001; p=0,001). There was no significant correlation regarding t2 MRI, operation time, grading, subtype and histopathological features (quantity of reticulin, calcifications and cell density) with the consistency of meningiomas.
Conclusions: The FA is a save predictor for the consistency of meningiomas. This information could be very useful in preoperative planning and decision whether the use of a CUSA is necessary or not. Further investigations should be done to evaluate the influence of the consistency on the grade of resection, recurrence and preservation of cranial nerve function, if involved.