Petroclival meningiomas: Magnetic resonance imaging factors predict tumor resectability and clinical outcome.
OBJECTIVE
Despite advances in skull base surgery, surgical removal of petroclival meningiomas (PCM) still poses a considerable neurosurgical challenge with regard to postoperative morbidity and the patients' long-term outcome. Knowledge of imaging features for PCM that might help to predict common risk factors encountered with tumor resection preoperatively is limited. The aim of this study was to clarify whether MRI features of PCM might predict tumor resectability and clinical outcome.


METHODS
A retrospective analysis of 18 cases of PCM treated surgically in our department between 2007 and 2013 was performed. Following radiological tumor features were compared to the extent of tumor resection and the patients' outcome: a) tumor diameter, b) calcification, c) tumor margin towards the brainstem, d) presence of an arachnoidal cleavage plane, e) brainstem edema, f) brainstem compression and g) tumor signal intensity on T2WI.


RESULTS
There was an excellent correlation between tumor resectability and preoperative findings with regard to the presence or absence of an arachnoidal cleavage plane and an irregular tumor margin towards the brainstem. Additionally, the presence of brainstem edema was significantly related to surgical morbidity, whereas a high tumor intensity on T2WI correlated significantly with soft tumor consistency and/or vascularity encountered during surgery.


CONCLUSIONS
As demonstrated in our series, PCM with an irregular tumor margin and absence of an arachnoidal plane towards the brainstem should be considered a high-risk group. In these cases, especially when additional brainstem edema is present, limited resection of tumor may be aspired to avoid postoperative morbidity.
Department of Neurosurgery, Hannover Medical School, Hannover, Germany. Electronic address: pirayesh03@web.de.
Ariyan
A
Pirayesh
Department of Neurosurgery, Hannover Medical School, Hannover, Germany.
Ioannis
I
Petrakakis
Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany.
Peter
P
Raab
Department of Neurosurgery, Hannover Medical School, Hannover, Germany.
Manolis
M
Polemikos
Department of Neurosurgery, Hannover Medical School, Hannover, Germany.
Joachim K
JK
Krauss
Department of Neurosurgery, Hannover Medical School, Hannover, Germany.
Makoto
M
Nakamura
D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D008579:Meningioma / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D019635:Neurosurgical Procedures; D017063:Outcome Assessment, Health Care; D010579:Petrous Bone / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D019292:Skull Base Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery
Brain MRI; Cranial nerves; Petroclival meningiomas; Skull base