Resection of subependymal giant cell astrocytoma guided by intraoperative magnetic resonance imaging and neuronavigation

Advanced intraoperative MRI in pediatric brain tumor surgery

Introduction: In the pediatric brain tumor surgery setting, intraoperative MRI (ioMRI) provides "real-time" imaging, allowing for evaluation of the extent of resection and detection of complications. The use of advanced MRI sequences could potentially provide additional physiological information that may aid in the preservation of healthy brain regions. This review aims to determine the added value of advanced imaging in ioMRI for pediatric brain tumor surgery compared to conventional imaging. Methods: Our systematic literature search identified relevant articles on PubMed using keywords associated with pediatrics, ioMRI, and brain tumors. The literature search was extended using the snowball technique to gather more information on advanced MRI techniques, their technical background, their use in adult ioMRI, and their use in routine pediatric brain tumor care. Results: The available literature was sparse and demonstrated that advanced sequences were used to reconstruct fibers to prevent damage to important structures, provide information on relative cerebral blood flow or abnormal metabolites, or to indicate the onset of hemorrhage or ischemic infarcts. The explorative literature search revealed developments within each advanced MRI field, such as multi-shell diffusion MRI, arterial spin labeling, and amide-proton transfer-weighted imaging, that have been studied in adult ioMRI but have not yet been applied in pediatrics. These techniques could have the potential to provide more accurate fiber tractography, information on intraoperative cerebral perfusion, and to match gadolinium-based T1w images without using a contrast agent. Conclusion: The potential added value of advanced MRI in the intraoperative setting for pediatric brain tumors is to prevent damage to important structures, to provide additional physiological or metabolic information, or to indicate the onset of postoperative changes. Current developments within various advanced ioMRI sequences are promising with regard to providing in-depth tissue information.

Therapeutic targeting of membrane-associated proteins in central nervous system tumors

The activity of the most complex system, the central nervous system (CNS) is profoundly regulated by a huge number of membrane-associated proteins (MAP). A minor change stimulates immense chemical changes and the elicited response is organized by MAP, which acts as a receptor of that chemical or channel enabling the flow of ions. Slight changes in the activity or expression of these MAPs lead to severe consequences such as cognitive disorders, memory loss, or cancer. CNS tumors are heterogeneous in nature and hard-to-treat due to random mutations in MAPs; like as overexpression of EGFRvIII/TGFβR/VEGFR, change in adhesion molecules α5β3 integrin/SEMA3A, imbalance in ion channel proteins, etc. Extensive research is under process for developing new therapeutic approaches using these proteins such as targeted cytotoxic radiotherapy, drug-delivery, and prodrug activation, blocking of receptors like GluA1, developing viral vector against cell surface receptor. The combinatorial approach of these strategies along with the conventional one might be more potential. Henceforth, our review focuses on in-depth analysis regarding MAPs aiming for a better understanding for developing an efficient therapeutic approach for targeting CNS tumors.

Novel management of glioma by molecular therapies, a review article

The most frequent type of brain tumors is Glioma which commonly appears initially in the neuroglia in the central nervous system. They grow steadily and generally do not outspread to neighboring tissue of the brain. By applying dominant remedial regimens, the patients would have negligible survival rates. Despite the achieved advances in conventional glioma therapy, it proved that a proper medication for glioma is not easily reachable. The glioma penetration nature and accumulate resistance considerably limit the remedial options. Superior explanation of the glioma complex pathobiology and characterization of biological proteogenomic may finally open new approaches for the outlining of extra artificial and impressive combination regimens. This aim could be achieved by exclusively outfitting advanced techniques of neuroimaging, terminating synthesis of DNA via genes that activated via prodrugs, experimental technique of gene therapy via conciliating genes of gliomagenesis, targeting miRNA-mRNA activity of oncogenic, applying stem cell therapy for combining inhibitors of Hedgehog-Gli, adaptive transmission of chimeric immunoreceptors T cells, incorporate inhibitors of regulators of the immune system with conventional remedial modalities and additionally using tumor cell lysates as sources of antigen for efficient evacuation of particular stem cells of tumor via cytotoxic T lymphocytes. Consequently, in this study the authors trying to survey the latest progressions related to the molecular procedures connected with the formation of glial tumors in addition to the radiation, surgery and chemotherapy limitations. Additionally, the novel strategies of molecular remedies and their procedure for the prosperous treatment of glioma will be discussed.

Surgery for subependymal giant cell astrocytomas in children with tuberous sclerosis complex

OBJECTIVE

Subependymal giant cell astrocytomas (SEGAs) are low-grade intraventricular glial tumors that develop in 10-15% of patients with tuberous sclerosis complex; they often cause hydrocephalus and are potentially accessible to a surgical treatment. Our aim is to evaluate morbidity and results after surgery in symptomatic and asymptomatic patients.

METHOD

We present a retrospective series of 18 pediatric patients operated on for SEGA between 2006 and 2016 at our institution. We reviewed surgical indications, preoperative clinical and radiologic data, surgical management, and clinical and radiological follow-up.

RESULTS

Mean age at surgery was 10.7 years. The surgical decision was based on clinical signs of raised intracranial pressure due to hydrocephalus in 8 and on radiological findings without any clinical signs in the other 10 patients (increased in SEGA volume with or without ventricular enlargement). Surgical treatment consisted in a frontal trans-ventricular microsurgical approach in 17 patients and an endoscopic approach in 1. External ventricular drainage was placed in all the patients but 1. Ventriculoperitoneal shunting (VPS) became necessary in 6 patients, all of them presenting with a preoperative active hydrocephalus. Morbidity appeared very low with meningitis occurring in 1 patient. Resection was complete in 15 children with no recurrence during a mean follow-up of 5.25 years and incomplete in 3 requiring a second surgery.

CONCLUSION

Surgery of SEGA represents a very effective treatment with low morbidity and no mortality in the present series. In patients operated before the onset of clinical signs of hydrocephalus, internal VPS could be avoided whereas in others, an additional shunt surgery became necessary. This gives arguments in favor of a regular MRI surveillance in tuberous sclerosis complex patients with SEGA in order to best propose resective surgery once a growth of tumor and/or ventricular size have been confirmed but before raised intracranial pressure occurs.

Insights into molecular therapy of glioma: current challenges and next generation blueprint

Glioma accounts for the majority of human brain tumors. With prevailing treatment regimens, the patients have poor survival rates. In spite of current development in mainstream glioma therapy, a cure for glioma appears to be out of reach. The infiltrative nature of glioma and acquired resistance substancially restrict the therapeutic options. Better elucidation of the complicated pathobiology of glioma and proteogenomic characterization might eventually open novel avenues for the design of more sophisticated and effective combination regimens. This could be accomplished by individually tailoring progressive neuroimaging techniques, terminating DNA synthesis with prodrug-activating genes, silencing gliomagenesis genes (gene therapy), targeting miRNA oncogenic activity (miRNA-mRNA interaction), combining Hedgehog-Gli/Akt inhibitors with stem cell therapy, employing tumor lysates as antigen sources for efficient depletion of tumor-specific cancer stem cells by cytotoxic T lymphocytes (dendritic cell vaccination), adoptive transfer of chimeric antigen receptor-modified T cells, and combining immune checkpoint inhibitors with conventional therapeutic modalities. Thus, the present review captures the latest trends associated with the molecular mechanisms involved in glial tumorigenesis as well as the limitations of surgery, radiation and chemotherapy. In this article we also critically discuss the next generation molecular therapeutic strategies and their mechanisms for the successful treatment of glioma.