Tag: volumetry

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Quantitative versus qualitative blood amount assessment as a predictor for shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage

J Neurosurg 131:1743–1750, 2019

Reliable tools are lacking to predict shunt-dependent hydrocephalus (SDHC) development after aneurysmal subarachnoid hemorrhage (aSAH). Quantitative volumetric measurement of hemorrhagic blood is a good predictor of SDHC but might be impractical in the clinical setting. Qualitative assessment performed using scales such as the modified Fisher scale (mFisher) and the original Graeb scale (oGraeb) is easier to conduct but provides limited predictive power. In between, the modified Graeb scale (mGraeb) keeps the simplicity of the qualitative scales yet adds assessment of acute hydrocephalus, which might improve SDHC-predicting capabilities. In this study the authors investigated the likely capabilities of the mGraeb and compared them with previously validated methods. This research also aimed to define a tailored mGraeb cutoff point for SDHC prediction.

METHODS The authors performed retrospective analysis of patients admitted to their institution with the diagnosis of aSAH between May 2013 and April 2016. Out of 168 patients, 78 were included for analysis after the application of predefined exclusion criteria. Univariate and multivariate analyses were conducted to evaluate the use of all 4 methods (quantitative volumetric assessment and the mFisher, oGraeb, and mGraeb scales) to predict the likelihood of SDHC development based on clinical data and blood amount assessment on initial CT scans.

RESULTS The mGraeb scale was demonstrated to be the most robust predictor of SDHC, with an area under the curve (AUC) of 0.848 (95% CI 0.763–0.933). According to the AUC results, the performance of the mGraeb scale was significantly better than that of the oGraeb scale (c 2 = 4.49; p = 0.034) and mFisher scale (c 2 = 7.21; p = 0.007). No statistical difference was found between the AUCs of the mGraeb and the quantitative volumetric measurement models (c = 12.76; p = 0.23), but mGraeb proved to be the simplest model since it showed the lowest Akaike information criterion (66.4), the lowest Bayesian information criterion (71.2), and the highest R 2 Nagelkerke coefficient (39.7%). The initial mGraeb showed more than 85% specificity for predicting the development of SDHC in patients presenting with a score of 12 or more points.

CONCLUSIONS According to the authors’ data, the mGraeb scale is the simplest model that correlates well with SDHC development. Due to limited scientific evidence of treatments aimed at SDHC prevention, we propose an mGraeb score higher than 12 to identify patients at risk with high specificity. This mGraeb cutoff point might also serve as a useful prognostic tool since patients with SDHC after aSAH have worse functional outcomes.

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Correlation of volumetric growth and histological grade in 50 meningiomas

Acta Neurochir (2017) 159:2169–2177

Advances in radiological imaging techniques have enabled volumetric measurements of meningiomas to be easily monitored using serial imaging scans. There is limited literature on the relationship between tumour growth rates and the WHO classification of meningiomas despite tumour growth being a major determinant of type and timing of intervention. Volumetric growth has been successfully used to assess growth of low-grade glioma; however, there is limited information on the volumetric growth rate (VGR) of meningiomas. This study aimed to determine the reliability of VGR measurement in patients with meningioma, assess the relationship between VGR and 2016 WHO grading as well as clinical applicability of VGR in monitoring meningioma growth.

Methods All histologically proven intracranial meningiomas that underwent resection in a single centre between April 2009 and April 2014 were reviewed and classified according to the 2016 edition of the Classification of the Tumours of the CNS. Only patients who had two pre-operative scans that were at least 3 months apart were included in the study. Two authors performed the volumetric measurements using the Slicer 3D software independently and the inter-rater reliability was assessed. Multiple regression analyses of factors affecting the VGR and VDE of meningiomas were performed using the R statistical software with p < 0.05 considered to be statistically significant.

Results Of 548 patients who underwent resection of their meningiomas, 66 met the inclusion criteria. Sixteen cases met the exclusion criteria (NF2, spinal location, previous surgical or radiation treatment, significant intra-osseous component and poor quality imaging). Forty-two grade I and 8 grade II meningiomas were included in the analysis. The VGR was significantly higher for grade II meningiomas. Using receiver-operator characteristic (ROC) curve analysis, the optimal threshold that distinguishes between grade I and II meningiomas is 3 cm3/year. Higher histological grade, high initial tumour volume, MRI T2-signal hyperintensity and presence of oedema were found to be significant predictors of higher VGR.

Conclusion Reliable tools now exist to evaluate and monitor volumetric growth of meningiomas. Grade II meningiomas have significantly higher VGR compared with grade I meningiomas and growth of more than 3 cm3/year is strongly suggestive of a higher grade meningioma. A larger, multi-centre prospective study to investigate the applicability of velocity of growth to predict the outcome of patients with meningioma is warranted.

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Effect of dural detachment on long-term tumor control for meningiomas treated using Simpson Grade IV resection

Effect of dural detachment on long-term tumor control for meningiomas treated using Simpson Grade IV resection

J Neurosurg 119:1373–1379, 2013

Meningiomas treated by subtotal or partial resection are associated with significantly shorter recurrencefree survival than those treated by gross-total resection. The Simpson grading system classifies incomplete resections into a single category, namely Simpson Grade IV, with wide variations in the volume and location of residual tumors, making it complicated to evaluate the achievement of surgical goals and predict the prognosis of these tumors. Authors of the present study investigated the factors related to necessity of retreatment and tried to identify any surgical nuances achievable with the aid of modern neurosurgical techniques for meningiomas treated using Simpson Grade IV resection.

Methods. This retrospective analysis included patients with WHO Grade I meningiomas treated using Simpson Grade IV resection as the initial therapy at the University of Tokyo Hospital between January 1995 and April 2010. Retreatment was defined as reresection or stereotactic radiosurgery due to postoperative tumor growth.

Results. A total of 38 patients were included in this study. Regrowth of residual tumor was observed in 22 patients with a mean follow-up period of 6.1 years. Retreatment was performed for 20 of these 22 tumors with regrowth. Risk factors related to significantly shorter retreatment-free survival were age younger than 50 years (p = 0.006), postresection tumor volume of 4 cm3 or more (p = 0.016), no dural detachment (p = 0.001), and skull base location (p = 0.016). Multivariate analysis revealed that no dural detachment (hazard ratio [HR] 6.42, 95% CI 1.41–45.0; p = 0.02) and skull base location (HR 11.6, 95% CI 2.18–218; p = 0.002) were independent risk factors for the necessity of early retreatment, whereas postresection tumor volume of 4 cm3 or more was not a statistically significant risk factor.

Conclusions. Compared with Simpson Grade I, II, and III resections, Simpson Grade IV resection includes highly heterogeneous tumors in terms of resection rate and location of the residual mass. Despite the difficulty in analyzing such diverse data, these results draw attention to the favorable effect of dural detachment (instead of maximizing the resection rate) on long-term tumor control. Surgical strategy with an emphasis on detaching the tumor from the affected dura might be another important option in resection of high-risk meningiomas not amenable to gross-total resection.

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Quantification of Glioma Removal by Intraoperative High-Field Magnetic Resonance Imaging: An Update

Neurosurgery 69:852–863, 2011 DOI: 10.1227/NEU.0b013e318225ea6b

The beneficial role of the extent of resection (EOR) in glioma surgery in correlation to increased survival remains controversial. However, common literature favors maximum EOR with preservation of neurological function, which is shown to be associated with a significantly improved outcome.

OBJECTIVE: In order to obtain a maximum EOR, it was examined whether high-field intraoperative magnetic resonance imaging (iMRI) combined with multimodal navigation contributes to a significantly improved EOR in glioma surgery.

METHODS: Two hundred ninety-three glioma patients underwent craniotomy and tumor resection with the aid of intraoperative 1.5 T MRI and integrated multimodal navigation. In cases of remnant tumor, an update of navigation was performed with intraoperative images. Tumor volume was quantified pre- and intraoperatively by segmentation of T2 abnormality in low-grade and contrast enhancement in high-grade gliomas.

RESULTS: In 25.9% of all cases examined, additional tumor mass was removed as a result of iMRI. This led to complete tumor resection in 20 cases, increasing the rate of grosstotal removal from 31.7% to 38.6%. In 56 patients, additional but incomplete resection was performed because of the close location to eloquent brain areas. Volumetric analysis showed a significantly (P , .01) reduced mean percentage of tumor volume following additional further resection after iMRI from 33.5% 6 25.1% to 14.7% 6 23.3% (World Health Organization [WHO] grade I, 32.8% 6 21.9% to 6.1% 6 18.8%; WHO grade II, 24.4% 6 25.1% to 10.8% 6 11.0%; WHO grade III, 35.1% 6 27.3% to 24.8% 6 26.3%; WHO grade IV, 34.2% 6 23.7% to 1.2% 6 16.2%).

CONCLUSION: MRI in conjunction with multimodal navigation and an intraoperative updating procedure enlarges tumor-volume reduction in glioma surgery significantly without higher postoperative morbidity.

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The natural history of intracranial meningiomas

J Neurosurg 114:1250–1256, 2011. DOI: 10.3171/2010.12.JNS101623

Despite the increased detection of incidental or small meningiomas, the lesion’s natural history is largely unknown.

Methods. One year or longer of follow-up was conducted in 244 patients with 273 meningiomas managed conservatively by a single surgeon between 2003 and 2008. Data were stratified according to age, sex, tumor location, symptoms, initial tumor diameter, calcification, MR imaging intensity, and edema. Linear tumor growth was defined as a 2-mm or larger increase in the maximum diameter in any direction of the tumor. Volumetric analysis (ImageJ version 1.43) was also conducted in 154 of 273 meningiomas for which complete radiological data were available in the form of DICOM files throughout the follow-up period. A volume increase greater than 8.2% was regarded as significant because the preliminary volumetry based on 20 randomly selected meningiomas showed that the average SD was 4.1%.

Results. Linear growth was observed in 120 tumors (44.0%) with a mean follow-up of 3.8 years. Factors related to tumor growth were age of 60 or younger (p = 0.0004), absence of calcification (p = 0.027), MR imaging T2 signal hyperintensity (p = 0.021), and edema (p = 0.018). Kaplan-Meier analysis and Cox proportional hazards regression analysis revealed that age 60 or younger (hazard ratio [HR] 1.54, 95% CI 1.05–2.30, p = 0.026), initial tumor diameter greater than 25 mm (HR 2.23, 95% CI 1.44–3.38, p = 0.0004), and the absence of calcification (HR 4.57, 95% CI 2.69–8.20, p < 0.0001) were factors associated with a short time to progression. Volumetric growth was seen in 74.0% of the cases. Factors associated with a higher annual growth rate were male sex (p = 0.0002), initial tumor diameter greater than 25 mm (p < 0.0001), MR imaging T2 signal hyperintensity (p = 0.0001), presence of symptoms (p = 0.037), and edema (p < 0.0001).

Conclusions. Although the authors could obtain variable results depending on the measurement method, the data demonstrate patients younger than 60 years of age and those with meningiomas characterized by hyperintensity on T2-weighted MR imaging, no calcification, diameter greater than 25 mm, and edema need to be observed more closely. Volumetry was more sensitive to detecting tumor growth than measuring the linear diameter.

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