Predicting IDH Mutation Status of Grade 2-4 Gliomas with DTI Parameters Derived from Model-based DTI and Model-free Q-Sampling Imaging Reconstructions

OBJECTIVE

To determine if diffusion tensor imaging (DTI) parameters acquired with model-based DTI and model-free Q-sampling imaging (GQI) reconstructions may noninvasively predict isocitrate dehydrogenase (IDH) mutational status in patients with grade 2-4 gliomas.

METHODS

Forty patients with known IDH genotype (28 IDH wild-type; 12 IDH mutant) who underwent preoperative DTI evaluation on a 3 Tesla MRI scanner were retrospectively analyzed. Absolute values obtained from model-based and model-free reconstructions were compared. Using the intraclass correlation coefficient, interobserver agreement was assessed for various sampling techniques. Variables having statistically significant distributions between IDH groups were subjected to a receiver operating characteristic (ROC) analysis. Using multivariable logistic regression analysis, independent predictors, if present, were identified and a model was developed.

RESULTS

Six imaging parameters (3 from model-based DTI and 3 from model-free GQI reconstructions) showed statistically significant differences between groups (p <0.001, power >0.97), with very high correlation to each other (p <0.001). Age difference between the groups was statistically significant (p <0.001). Optimal logistic regression model comprised a GQI-based parameter and age, which were independent predictors as well, producing an area under the ROC curve, accuracy, sensitivity, and specificity of 0.926, 85%, 75%, and 89%, respectively. Using the GQI reconstruction feature alone with a cut-off of 1.60, an 85% of accuracy was also achieved with ROC analysis.

CONCLUSIONS

The imaging parameters acquired from model-based DTI and model-free GQI reconstructions, combined with the clinical variable age, may have the ability to non-invasively predict the IDH genotype in gliomas, either alone or in particular combinations.

Clinical Study of Decompressive Craniectomy in Children

AIM

To evaluate the clinical characteristics of children who recently underwent decompressive craniectomy (DC) due to elevated intracranial pressure (ICP) correlated to head trauma or other causes, such as ischemic insult.

MATERIAL AND METHODS

Twelve patients aged ≤17 years who underwent DC due to elevated ICP between 2013 and 2018 were included in the study. The clinical status of the participants, radiological characteristics, type and timing of surgery, and outcomes were recorded.

RESULTS

Three female and nine male patients with a mean age of 10 years were included. The initial average Glasgow Coma Scale score was 6 (3-12). All patients presented with signs of diffuse cerebral edema and subdural hematoma of various sizes along with other intracranial pathologies. Only one patient required bilateral frontal craniectomy. In the postoperative period, three patients died, and three had severe disability.

CONCLUSION

With the increasing use and success of DC in adults, this procedure can also be effective in children. Considering brain differences in children, large and well-structured clinical trials must be conducted to prevent complications and to identify the best technique, timing, and benefits of DC for children.

Unilateral endoscopic optic nerve decompression for idiopathic intracranial hypertension: a series of 10 patients

OBJECTIVE

Several surgical treatment modalities, including lumboperitoneal or ventriculoperitoneal shunt surgery, subtemporal decompression, endovascular venous sinus stenting, optic nerve decompression (OND), were used in the management of idiopathic intracranial hypertension (IIH). Each surgical technique has different advantages and disadvantages. Endoscopic OND is rarely used in the management of IIH. There are only four reported cases. The aim of this study is to describe the surgical results of patients treated with this less invasive surgical technique.

METHODS

A series of 10 consecutive cases of unilateral OND was reviewed. Between December 2008 and December 2012 these patients underwent the endoscopic approach without nerve sheath opening. Presenting symptoms, neurological examination findings, magnetic resonance venography imaging results, fundoscopic and visual acuity examination findings, and automated perimetry test results were recorded. Perioperative results, including complications and length of hospital stay, were evaluated. Findings at follow-up evaluations were also recorded.

RESULTS

This report is the first series of unilateral OND performed using the endoscopic approach. The mean patient age was 34.1 years (range, 9-49 years); there were nine female and one male patients. Visual impairment was the main symptom in this patient group, whereas headache was a secondary complaint. The patients were first managed with medical treatment for at least 3 months. Unilateral endoscopic OND was performed on the side with the most visual failure. Mean follow-up was 28.4 months (range, 8-55 months). The visual field defects and visual acuity improved in eight of nine patients, whereas papilloedema improved in seven of nine patients. Also headaches resolved in four of seven patients. There were no complications in this relatively small series.

CONCLUSIONS

The surgical treatment of IIH by using the unilateral endoscopic OND technique is a safe and effective method in the hands of experienced surgeons with advanced endoscopic skills. A collaboration with the ophthalmology team is needed for the follow-up. Further studies with larger patient numbers is needed to compare unilateral endoscopic OND technique with the current techniques used in the surgical management of IIH.