Tag: diagnostic accuracy

Posted on

High-grade glioma: combined use of 5-aminolevulinic acid and intraoperative ultrasound for resection and a predictor algorithm for detection

J Neurosurg 143:323–331, 2025

Combining 5-aminolevulinic acid (5-ALA) fluorescence and intraoperative ultrasound (ioUS) significantly improved the sensitivity and specificity for detecting high-grade glioma during surgery, compared to either technique alone. A machine learning algorithm (HGGPredictor) further enhanced intraoperative tumor margin prediction, suggesting a new standard for safer, more effective resections.

• Combining 5-ALA fluorescence and intraoperative ultrasound (ioUS) improves the accuracy of high-grade glioma (HGG) resection compared to using either method alone.

• 5-ALA shows higher sensitivity (84.9%), while ioUS provides higher specificity (84.5%); combined, they reach sensitivity of 91% and specificity of 86%.

• The combined approach is especially valuable for maximizing tumor removal while minimizing neurological damage, particularly near eloquent brain regions.

• A machine learning algorithm (HGGPredictor) was developed to predict tumor presence during surgery based on 5-ALA and ioUS results.

• The study included 72 patients and 301 biopsies, with histological analysis as the reference standard.

• The benefit of combination is greatest for strong fluorescence or hyperechogenicity; ioUS is particularly helpful when 5-ALA fluorescence is weak.

• The combined method is accessible and can be integrated into existing surgical protocols without major additional costs.

• Limitations include single-center design and lack of a control group, but results suggest a new standard for HGG resection.

 

Posted on

MRI combined with PET-CT of different tracers to improve the accuracy of glioma diagnosis

Neurosurg Rev (2019) 42:185–195

Based on studies focusing on positron emission tomography (PET)-computed tomography (CT) combined with magnetic resonance imaging (MRI) in the diagnosis of glioma, we conducted a systematic review and meta-analysis evaluating the pros and cons and the accuracy of different examinations. PubMed and Cochrane Library were searched. The search was conducted until April 2017. Two reviewers independently conducted the literature search according to the criteria set initially. Based on the exclusion criteria, 15 articles are included in this study.

Of all studies that used MRI examination, there are five involving 18F-fluorodeoxyglucose- PET, five involving 11C-methionine-PET, five involving 18F-fluoro-ethyl-tyrosine-PET, and three involving 18Ffluorothymidine- PET. Due to the limitations such as lack of data, small sample size, and unrepresentative studies, we use a non-quantitative methodology.

MRI examination can provide the anatomy information of glioma more clearly. PET-CT examinations based on tumor metabolism using different tracers have more advantages in determining the degree of glioma malignancy and boundaries. However, information provided by PET-Craneotomía of different tracers is not the same. With respect to the novel hybrid MRI/PET examination equipment proposed in recent years, the combination of MRI and PET-CT can definitively improve the diagnostic accuracy of glioma.

Posted on

Accurate Delineation of Glioma Infiltration by Advanced PET/MR Neuro-Imaging (FRONTIER Study)

f1-largeNeurosurgery 79:535–540, 2016

Glioma imaging, used for diagnostics, treatment planning, and followup, is currently based on standard magnetic resonance imaging (MRI) modalities (T1 contrast-enhancement for gadolinium-enhancing gliomas and T2 fluid-attenuated inversion recovery hyperintensity for nonenhancing gliomas). The diagnostic accuracy of these techniques for the delineation of gliomas is suboptimal.

OBJECTIVE: To assess the diagnostic accuracy of advanced neuroimaging compared with standard MRI modalities for the detection of diffuse glioma infiltration within the brain.

METHODS: A monocenter, prospective, diagnostic observational study in adult patients with a newly diagnosed, diffuse infiltrative glioma undergoing resective glioma surgery. Forty patients will be recruited in 3 years. Advanced neuroimaging will be added to the standard preoperative MRI. Serial neuronavigated biopsies in and around the glioma boundaries, obtained immediately preceding resective surgery, will provide histopathologic and molecular characteristics of the regions of interest, enabling comparison with quantitative measurements in the imaging modalities at the same biopsy sites.

DISCUSSION: In this clinical study, we determine the diagnostic accuracy of advanced imaging in addition to standard MRI to delineate glioma. The results of our study can be valuable for the development of an improved standard imaging protocol for glioma treatment.

EXPECTED OUTCOME: We hypothesize that a combination of positron emission tomography, MR spectroscopy, and standard MRI will have a superior accuracy for glioma delineation compared with standard MRI alone. In addition, we anticipate that advanced imaging will correlate with the histopathologic and molecular characteristics of glioma.

Posted on

Brain Imaging in Chronic Epilepsy Patients After Depth Electrode (Stereoelectroencephalography) Implantation: Magnetic Resonance Imaging or Computed Tomography?

Depth electrode localization error

Neurosurgery 73:543–549, 2013

The accurate localization of depth electrodes in epilepsy surgery is important for correct interpretation of stereoelectroencephalography recordings and neurosurgical resection. Unfortunately, image quality in postimplantation magnetic resonance imaging (MRI) is degraded by metal artifacts. The registration of postimplantation computed tomography (CT) or MRI to preimplantation (artifact-free) MRI facilitates electrode imaging and optimal visualization of brain anatomy. However, registration errors negatively affect electrode localization accuracy.

OBJECTIVE: To compare the relative registration deviation between postimplantation CT and MRI with preimplantation MRI.

METHODS: Retrospectively, 14 pharmacoresistant epilepsy patients were included who underwent stereotactic insertion of multiple depth electrodes and preimplantation and postimplantation MRI and postimplantation CT. Postimplantation MRI and CT image sets were registered to preimplantation MRI. The registration error between the registered postimplantation MRI and CT was quantified by measuring the geometrical distance between the electrodes of the registered postimplantation CT and the postimplantation MRI.

RESULTS: The registration error of postimplantation imaging to preimplantation MRI was dependent on the algorithm used. After optimization, the smallest registration error was 1.22 6 0.29 mm (mean 6 SD) at the tip and 2.25 6 1.18 mm at the base of the electrode.

CONCLUSION: The good correspondence between the CT/MRI and the MRI/MRI registration suggests that either postimplantation MRI or CT is sufficient for accurate electrode localization. In case of postoperative morphological brain deformations, postimplantation MRI is still recommended.

Posted on

Strong 5-aminolevulinic acid-induced fluorescence is a novel intraoperative marker for representative tissue samples in stereotactic brain tumor biopsies

Neurosurg Rev (2012) 35:381–391 DOI 10.1007/s10143-012-0374-5

Stereotactic biopsies represent a routine neurosurgical procedure for the diagnosis of intracranial lymphomas and selected diffusely infiltrating gliomas. Acquisition of tissue samples that do not allow correct tumor typing and grading is, however, not uncommon. Five-aminolevulinic acid (5-ALA) has been shown to accumulate in malignant tumor tissue. The aim of this study was to prospectively investigate the clinical usability of 5-ALA for intraoperative detection of representative tissue in stereotactic tumor biopsies.

Fifty consecutive patients underwent frameless stereotactic biopsy for a suspected brain tumor. 5-ALA was administered 4 h before anesthesia. Serial biopsy samples were obtained and intraoperatively checked for 5-ALA fluorescence (strong, vague, or none) using a modified neurosurgical microscope. All samples were examined for the presence of representative tumor tissue according to neuroimaging (MRI, positron emission tomography, and/or chemical shift imaging) and histopathological parameters.

Visible 5-ALA fluorescence was observed in 43/50 patients (strong in 39 and vague fluorescence in four cases). At biopsy target, 52/53 samples of glioblastomas, 9/10 samples of gliomas grade III, and 14/16 samples of lymphomas revealed strong 5-ALA fluorescence. Samples with strong 5-ALA fluorescence were only observed at, but not outside the biopsy target. All tissue samples with strong 5-ALA fluorescence were representative according to our neuroimaging and histopathological criteria (positive predictive value of 100%). Our data indicate that strong 5-ALA fluorescence is a reliable and immediately available intraoperative marker of representative tumor tissue of malignant gliomas and intracranial lymphomas in stereotactic biopsies. Thereby, the application of 5- ALA in stereotactic brain tumor biopsies may in future reduce costs for operating room and neuropathology and may decrease procedure-related morbidity.

 

Posted on

Percutaneous biopsy of lesions in the cavernous sinus region through the foramen ovale: diagnostic accuracy and limits in 50 patients

J Neurosurg 116:390–398, 2012.DOI: 10.3171/2011.10.JNS11783

The cavernous sinus and surrounding regions—specifically the Meckel cave, posterior sector of the cavernous sinus itself, and the upper part of the petroclival region—are the location of a large variety of lesions that require individual consideration regarding treatment strategy. These regions may be reached for biopsy by a percutaneous needle inserted through the foramen ovale. The aim of this retrospective study was to evaluate the diagnostic accuracy of percutaneous biopsy in a consecutive series of 50 patients referred for surgery between 1991 and 2010.

Methods. Seven biopsies (14%) were unproductive and 43 (86%) were productive, among which 28 lesions subsequently underwent histopathological examination during a second (open) surgery. To evaluate the diagnostic accuracy of the procedure, results from surgery were compared with those from the biopsy.

Results. Sensitivity of the percutaneous biopsy was 0.83 (95% CI 0.52–0.98), specificity was 1 (95% CI 0.79–1), and k coefficient was 0.81.

Conclusions. Because of its valuable diagnostic accuracy, percutaneous biopsy of the cavernous sinus and surrounding regions should be performed in patients with parasellar masses when neuroimaging does not provide sufficient information of a histopathological nature. This procedure would enable patients to obtain the most appropriate therapy, such as resective surgery, corticosteroids, chemotherapy, radiotherapy, or radiosurgery.

Proudly powered by WordPress