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This research aimed to determine whether an adequate surgical approach can be chosen based on clearly defined values of anatomical landmarks (tentorial angle) and tumor size and extension. We conducted a retrospective analysis of patients operated on because of pineal tumors. The cohort was divided depending on the surgical approach. On preoperative magnetic resonance imaging, we measured maximal diameters, tumor volume, and tumor propagation. In the group of patients operated with the supracerebellar infratentorial approach, we also tested the correlation of tentorial angle with residual tumor. Differences among groups in resection, complications rate, and outcome were tested by the χ2 test. Finally, in both groups, the correlation of residual tumor with tumor volume, propagation, and diameters was tested using the receiver operating characteristic curve. In the group operated with a supracerebellar approach, total resection was achieved in 78% of the patients. The critical value of cranio-caudal diameter correlated with tumor residue was 31 mm, for lateral-lateral diameter 25 mm, for the lateral extension 14 mm, and tumor volume 12 cm3. Tentorial angle did not influence the extent of the resection. In the group operated with an occipital transtentorial approach, the critical tumor volume related to tumor residue was 9 mm3, anterior-posterior diameter 29 mm, and cranio-caudal diameter 28 mm. The extent of the resection was significantly higher in the supracerebellar group. In both approaches, tumors larger than 3 cm show an increased risk of subtotal resection. Except when most tumor volume is localized above the venous system, we advocate a supracerebellar corridor as an effective approach that is not limited by tentorial angle. [ABSTRACT FROM AUTHOR]

Objective Atypical and anaplastic meningiomas (World Health Organization classification grade II and III) represent a small and heterogeneous subgroup of meningiomas that has a more aggressive biological nature and higher frequency of recurrence. The atypical form accounts for 4.7%–7.2%, whereas the anaplastic type accounts for 1%–2.8% of all meningiomas. The aim of this study is to evaluate the role of postoperative radiotherapy on overall survival and progression-free survival in patients operated for atypical and anaplastic meningiomas. Methods A retrospective analysis of the patients operated at the Clinic of Neurosurgery, Clinical Center of Serbia, Belgrade, between January 1, 1995 and December 31, 2006 was performed. In that period 88 lesions met the histologic criteria for atypical (75) and anaplastic (13) meningiomas. Postoperative radiotherapy was conducted in 63.6% of patients. Results At a median follow-up of 67.4 months the overall survival was 68 months and the 5-year survival was about 54.5%. The median survival was 76 months with surgery and adjuvant radiotherapy and 40 months with surgery alone (log rank = 7.4; P = 0.006). Recurrent disease occurred in 58 patients (65.9%). Median time between first surgery and tumor recurrence in patients undergoing radiotherapy was 51 months, whereas in the nonirradiated group it was 24 months (log rank = 17.7; P < 0.001). Multivariate analysis identified as recurrence-predicting factors anaplastic histotype (hazard ratio = 2.9; P = 0.003) and postoperative radiotherapy (hazard ratio = 4.5; P < 0.001). Conclusions The addition of adjuvant radiotherapy to surgery for atypical and anaplastic meningiomas resulted in a clinically meaningful and statistically significant survival benefit. [ABSTRACT FROM AUTHOR]