Mistry, Akshitkumar M.

Abstract BACKGROUND One study has investigated postoperative growth rates following subtotal resection of petroclival meningiomas utilizing linear measurements, which are insensitive to the multidimensional complex growth of meningiomas, to estimate tumor volume. OBJECTIVE To describe petroclival meningioma growth patterns following less-than-complete resection utilizing volumetric analysis and to identify variables associated with tumor progression. METHODS Patients with surgically resected WHO grade I petroclival meningiomas were retrospectively reviewed (1999-2015). Image analysis software was utilized to perform volumetric analyses of tumor size and growth on serial MRI studies. The impact of preoperative and postoperative variables on tumor growth after subtotal resection was analyzed. An increase in tumor volume of at least 20% was defined as “tumor growth.” RESULTS Twenty-three patients had immediate preoperative and serial postoperative MRI studies available for review. The mean preoperative tumor volume was 20.9 cm 3 (range 0.4-54.6). The mean extent of resection was 75.5% (range 31.5%-100.0%). At a mean follow-up of 24.8 mo, 12 tumors (66.7%) exhibited radiological tumor growth, while 6 tumors did not change in size. The median annual volumetric growth rate was 2.82 cm 3 /yr (range –0.34 to 10.1). Extent of resection and immediate postoperative tumor volume were significantly correlated with the annual volumetric growth rate following resection. At last follow-up, 3 (13%) patients required further intervention. CONCLUSION The majority of petroclival meningiomas exhibit growth following subtotal resection. Extent of resection is strongly associated with risk for disease progression following surgery.

Objectives: This study characterizes primary petroclival meningioma growth rates, before intervention, using volumetric analysis. In addition, predictors of growth are analyzed. Methods: Patients with previously untreated petroclival meningiomas were retrospectively reviewed (1999–2015). Image analysis software was used to perform volumetric analyses of tumor size and growth. Three-dimensional segmentation volumetric analyses were compared with volumes estimated utilizing three orthogonal dimensions. Tumor growth was defined as a 15% increase in volume. Results: Thirty-four patients who underwent at least two magnetic resonance imaging (MRI) studies before intervention were included. The mean age was 55.2 years, and 65.7% were women. The mean tumor volume at presentation was 5.6 cm 3 (range, 0.1–25.8 cm 3 ) as determined from segmentation volumetric analysis. At a mean follow-up of 44.5 months (range, 3.7–125.1 mo), 88.2% of tumors grew. The mean annual volumetric growth rate was 2.38 cm 3 /yr (−0.63 to 25.9 cm 3 /yr). Tumor volume, T2 hyperintensity within the tumor, peritumoral edema, and ataxia and/or cerebellar symptoms at presentation were all significantly associated with greater rates of tumor growth. Ultimately, 10 (29.4%) patients underwent treatment during the follow-up period. Conclusion: Our experience demonstrates that the vast majority (88%) of untreated petroclival meningiomas grow; the mean volumetric growth rate was noted to be 2.38 cm 3 /yr. We found a significant association between increased growth rate and larger tumor size at diagnosis, T2 hyperintensity within the tumor, peritumoral edema, and the presence of ataxia and/or cerebellar symptoms.