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Object The supraorbital eyebrow approach is a minimally invasive technique that offers wide access to the anterior skull base region and parasellar area through asubfrontal corridor. The use of neuroendoscopy allows one to extend the approach further to the pituitary fossa, the anterior third ventricle, the interpeduncular cistern, the anterior and medial temporal lobe, and the middle fossa. The supraorbital approach involves a limited skin incision, with minimal soft-tissue dissection and a small craniotomy, thus carrying relatively low approach-related morbidity. Methods All consecutive patients who underwent the endoscopic supraorbital eyebrow approach were retrospectively analyzed for lesion location, pathology, length of stay, complications, and cosmetic results. Results During a 56-month period, 97 patients (mean age 58.5 years) underwent an endoscopic eyebrow approach to resect extra- and intraaxial brain lesions. The most common pathologies treated were meningiomas (n = 41); craniopharyngiomas (n = 22); dermoid tumors (n = 7); metastases (n = 4); gliomas (n = 3); and other miscellaneous frontal, parasellar, and midbrain (n = 23) lesions. The median length of postoperative hospital stay was 2.7 days (range 1–8 days). In 82 patients a total removal of the lesion was performed, while in 15 patients a near-total or subtotal removal was achieved. There were no postoperative hematomas, cerebrospinal fluid leaks, or severe neurological deficits, with the exception of 2 cases of visual deterioration and 1 case each of meningitis, stroke, and third cranial nerve paresis. Other complications directly related to the approach included 2 cases of skin burn as a direct result of heat transmission from the microscope light, 1 case of right frontal palsy, 2 cases of frontal numbness, and 1 case of bone remodeling 1 year after surgery. Conclusions The endoscopic supraorbital eyebrow approach is a safe and effective minimally invasive approach to remove extra- and intraaxial anterior skull base, parasellar, and frontal lesions, promoting a rapid recovery and short hospital stay. The location of the eyebrow incision demands a meticulous cosmetic closure, but, with proper technique, cosmetic results are excellent.

Recent advance in molecular characterization of gliomas showed that patient prognosis and/or tumor chemosensitivity correlate with certain molecular signatures; however, this information is available only after tumor resection. If molecular information is available by routine radiological examinations, surgical strategy as well as overall treatment strategy could be designed preoperatively.With the aim to establish an imaging scoring system for preoperative diagnosis of molecular status in lower-grade gliomas (WHO grade 2 or 3, LrGGs), we investigated 8 imaging features available on routine CT and MRI in 45 LGGs (discovery cohort) and compared them with the status of 1p/19q codeletion, IDH mutations, and MGMT promoter methylation. The scoring systems were established based on the imaging features significantly associated with each molecular signature, and were tested in the another 52 LrGGs (validation cohort).For prediction of 1p/19q codeletion, the scoring system is composed of calcification, indistinct tumor border on T1, paramagnetic susceptibility effect on T1, and cystic component on FLAIR. For prediction of MGMT promoter methylation, the scoring system is composed of indistinct tumor border, surface localization (FLAIR), and cystic component. The scoring system for prediction of IDH status was not established. The 1p/19q score ≥ 3 showed PPV of 96.2% and specificity of 98.1%, and the MGMT methylation score ≥ 2 showed PPV of 77.4% and specificity of 67.6% in the entire cohort.These scoring systems based on widely available imaging information may help to preoperatively design personalized treatment in patients with LrGG.

Management of gliomas depends on histological diagnosis; there are, however, limitations to the systems presently used. Tumors in the same entity can have different clinical courses, especially when they are diagnosed as WHO grade II-III. Previous studies revealed that genetic subgrouping of gliomas provides useful information that could help establishment of treatment procedures on the basis of the genetic background of the tumors. Recently, the authors analyzed the chromosomal copy number aberrations (CNAs) of adult supratentorial gliomas by comparative genomic hybridization using microdissected tissue sections. The tumors were classified into subgroups according to chromosomal CNAs. WHO grade II-III gliomas contained a variety of genetic subgroups that correlated well with the clinical course. Of these, long progression-free survival was observed for tumors with +7q and those with -1p/19q, low-grade tumors of 2 major lineages, and, in our preliminary data, both were closely correlated with mutation of IDH1. Furthermore, in contrast with +7q tumors, the great majority of +7 or +7/-10q groups had wildtype IDH1. Genetic studies suggest that cytogenetic characterization may provide an additional classification system for gliomas, and new criteria could help to establish rational and objective means for analysis of treatment procedures.

Recent progress in neuro-oncology has validated the significance of genetic diagnosis in gliomas. We previously investigated IDH1/2 and TP53 mutations via Sanger sequencing for adult supratentorial gliomas and reported that PCR-based sequence analysis classified gliomas into three genetic subgroups that have a strong association with patient prognosis: IDH mutant gliomas without TP53 mutations, IDH and TP53 mutant gliomas, and IDH wild-type gliomas. Furthermore, this analysis had a strong association with patient prognosis. To predict genetic subgroups prior to initial surgery, we retrospectively investigated preoperative radiological data using CT and MRI, including MR spectroscopy (MRS), and evaluated positive 5-aminolevulinic acid (5-ALA) fluorescence as an intraoperative factor. We subsequently compared these factors to differentiate each genetic subgroup. Multiple factors such as age at diagnosis, tumor location, gadolinium enhancement, 5-ALA fluorescence, and several tumor metabolites according to MRS, such as myo-inositol (myo-inositol/total choline) or lipid20, were statistically significant factors for differentiating IDH mutant and wild-type, suggesting that these two subtypes have totally distinct characteristics. In contrast, only calcification, laterality, and lipid13 (lipid13/total Choline) were statistically significant parameters for differentiating TP53 wild-type and mutant in IDH mutant gliomas. In this study, we detected several pre- and intraoperative factors that enabled us to predict genetic subgroups for adult supratentorial gliomas and clarified that lipid13 quantified by MRS is the key tumor metabolite that differentiates TP53 wild-type and mutant in IDH mutant gliomas. These results suggested that each genetic subtype in gliomas selects the distinct lipid synthesis pathways in the process of tumorigenesis.