Person: HATİBOĞLU, MUSTAFA AZİZ
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Publication Metadata only Impact of surgical methodology on the complication rate and functional outcome of patients with a single brain metastasis(2015-05-01) PATEL, Akash J.; SUKI, Dima; Hatiboglu, MUSTAFA AZİZ; RAO, Vikas Y.; FOX, Benjamin D.; SAWAYA, Raymond; HATİBOĞLU, MUSTAFA AZİZOBJECT Brain metastases are the most common intracranial neoplasms and are on the increase. As radiation side effects are increasingly better understood, more patients are being treated with surgery alone with varying outcomes. The authors previously reported that en bloc resection of a single brain metastasis was associated with decreased incidences of leptomeningeal disease and local recurrence compared with piecemeal resection. However, en bloc resection is often feared to cause an increased incidence of postoperative complications. This study aimed to answer this question.Publication Open Access Can COVID-19 induce glioma tumorogenesis through binding cell receptors?(2020-11-01T00:00:00Z) Khan, I; Hatiboglu, MUSTAFA AZİZ; HATİBOĞLU, MUSTAFA AZİZPublication Open Access Toxicity of Radiosurgery for Brainstem Metastases.(2018-11-01) PATEL, A; DONG, T; ANSARI, S; COHEN-GADOL, A; WATSON, GA; MORAES, FY; NAKAMURA, M; MUROVIC, J; CHANG, SD; Hatiboglu, MUSTAFA AZİZ; CHUNG, C; MILLER, JC; LAUTENSCHLAEGER, T; HATİBOĞLU, MUSTAFA AZİZPublication Open Access Considerations for future novel human-infecting coronavirus outbreaks.(2020-08-29T00:00:00Z) Sinclair, G; Johnstone, P; Hatiboglu, MUSTAFA AZİZ; HATİBOĞLU, MUSTAFA AZİZUp until, June 13, 2020, >7,500,000 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and >400,000 deaths, across 216 countries, have been confirmed by the World Health Organization (WHO). With reference to the two previous beta-CoV outbreaks (SARS-CoV and middle east respiratory syndrome [MERS]), this paper examines the pathophysiological and clinical similarities seen across all three CoVs, with a special interest in the neuroinvasive capability and subsequent consequences for patients with primary or metastatic brain tumors. More widely, we examine the lessons learned from the management of such large-scale crises in the past, specifically looking at the South Korean experience of MERS and the subsequent shift in disaster management response to SARS-CoV-2, based on prior knowledge gained. We assess the strategies with which infection prevention and control can, or perhaps should, be implemented to best contain the spread of such viruses in the event of a further likely outbreak in the future.Publication Open Access Evaluation of Brainstem Subcortical Auditory Pathways with Diffusion Tensor Imaging After Gamma Knife Radiosurgery in Intracanalicular Vestibular Schwannoma(2021-01-01T00:00:00Z) Cesme, Dilek Hacer; Alkan, Alpay; Gultekin, Mehmet Ali; Sari, Lutfullah; Alkan, Gokberk; Seyithanoglu, Mehmet Hakan; Hatiboglu, Mustafa Aziz; ÇEŞME, DİLEK HACER; ALKAN, ALPAY; SEYİTHANOĞLU, MEHMET HAKAN; HATİBOĞLU, MUSTAFA AZİZObjective: To investigate changes in DTI (Diffusion Tensor Imaging) parameters in brainstem subcortical auditory pathways after Gamma Knife Radiosurgery (GKR) in patients with intracanalicular vestibular schwannoma (ICVS) and to analyze the relationship between tumor volume and ADC (apparent diffusion coefficient) and FA (fractional anisotropy) values. Method: Seventeen patients with ICVS were evaluated before and after GKR. ADC and FA values of the lateral lemniscus (LL) and inferior colliculus (IC) and tumor volume were calculated. Patients who responded to GKR were classified as Group 1 and those who did not respond adequately as Group 2. The relationship between ADC and FA values and changes in tumor volume were analyzed. Results: Tumor volume significantly decreased after GKR. ADC values obtained from the tumor increased after GKR (p:0.002). There was no significant difference in LL and IC before and after GKR in terms of FA and ADC values (n:17). There was a positive correlation between response to treatment and contralateral LL ADC values after GKR (p=0.005, r:0.652). There was a negative correlation between contralateral IC FA values after GKR and response to treatment (p=0.017, r: -0.568). There was a significant difference between Groups 1 and 2 in regards to contralateral LL ADC (p=0.03) and IC FA values (p=0.017). Conclusion: Since the cochlear nerve and subcortical auditory pathways have low regeneration potential after nerve damage, ADC and FA changes in LL and IC may be explained with the presence of intracanalicular tumors prior to GKR. Since GKR does not cause additional damage to the subcortical auditory pathways at the brainstem level, we think that GKR is a noninvasive treatment method that can be used safely in patients with ICVS.Publication Open Access Diffusion Tensor Imaging Features of the Auditory Pathways in Patients With Vestibular Schwannoma After Gamma Knife Radiosurgery(2021-03-01T00:00:00Z) ÇEŞME, DİLEK HACER; ALKAN, ALPAY; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; Alkan, Gokberk; KAYA, AHMET; MAYADAĞLI, Alpaslan; Akdur, Kerime; UYSAL, ÖMER; HATİBOĞLU, MUSTAFA AZİZ; ÇEŞME, DİLEK HACER; ALKAN, ALPAY; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; KAYA, AHMET; MAYADAĞLI, ALPASLAN; UYSAL, ÖMER; HATİBOĞLU, MUSTAFA AZİZObjective In this study, we aimed to investigate whether there is any change in diffusion tensor imaging (DTI) parameters in ipsilateral and contralateral auditory pathways after Gamma Knife radiosurgery (GKR) in patients with vestibular schwannoma (VS) and the relationship between radiosurgery variables. Methods Sixty-six patients were evaluated with MRI and DTI before and after GKR. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured from the bilateral lateral lemniscus (LL), inferior colliculus (IC), medial geniculate body (MGB), and Heschl's gyrus (HG). Results There was no significant difference in ADC and FA values obtained from bilateral LL, IC, and MGB before and after radiosurgery. However, there was a significant difference between pretreatment and post-radiosurgery contralateral HG ADC values. The ADC values obtained from the contralateral HG and IC positively correlated with the duration after radiosurgery. As the duration after radiosurgery increases, the difference between the ADC values obtained from ipsilateral and contralateral HG also increases. Conclusion The high ADC values in the contralateral HG after radiosurgery may indicate microstructural alterations such as demyelination and axonal loss. Radiation exposure doses to the brainstem and cochlea are the most important factors that can cause microstructural damage to the auditory pathways. When planning radiosurgery, extreme care should be taken to prevent the harmful effects of radiation on the auditory pathways.Publication Metadata only The efficacy of gamma knife radiosurgery in patients with trigeminal neuralgia: The initial experience of the Bezmialem Vakif University(2019-03-01T00:00:00Z) Akdag, Halil; Comert, Didem; Akdur, Kerime; Sakarcan, Ayten; Seyithanoglu, Hakan; HATİBOĞLU, MUSTAFA AZİZ; SEYİTHANOĞLU, MEHMET HAKAN; HATİBOĞLU, MUSTAFA AZİZBackground: Gamma knife stereotactic radiosurgery is, compared with surgical treatment, a less invasive treatment option for patients with trigeminal neuralgia (TN).Publication Open Access Importance of Pre-treatment Fractional Anisotropy Value in Predicting Volumetric Response in Patients with Meningioma Treated with Gamma Knife Radiosurgery.(2021-01-28T00:00:00Z) Cesme, Dilek Hacer; Alkan, Alpay; Sari, Lutfullah; Yabul, Fatma; Temur, Hafize Otcu; Aykan, Mahmut Esat; Hatiboglu, Mustafa Aziz; Seyithanoglu, Mehmet Hakan; ÇEŞME, DİLEK HACER; ALKAN, ALPAY; SEYİTHANOĞLU, MEHMET HAKAN; HATİBOĞLU, MUSTAFA AZİZBackground: The importance of pre-treatment Diffusion Tensor Imaging (DTI) parameters in determining the response to treatment after radiosurgery in patients with meningioma has not yet been clearly revealed. Objective: This study was conducted to determine tumor volume changes in terms of radiological response in patients with meningioma treated with Gamma Knife Radiosurgery (GKR) and to analyze the relationship between Total Tumor Volume (TTV) and Diffusion Tensor Imaging (DTI) parameters. In addition, we investigated whether the response to treatment can be predicted by pre-radiosurgery DTI findings. Methods: Fifty-four patients were assessed using MRI and DTI before and after GKR. Mean Diffusivity (MD), Fractional Anisotropy (FA), Radial Diffusivity (RD), and TTV of tumour were determined. Patients with 10% or more decrease in TTV after GKR were classified as group 1 and those with less than 10% decrease in volume or increase in volume were considered group 2. The relationships between MD, RD, and FA values and TTV were investigated. Results: A decrease of 46.34% in TTV was detected in group 1 after GKR, while TTV increased by 42.91% in group 2. The lowest pre-treatment FA value was detected in group 1. In addition, after GKR, FA values showed a significant increase in group 1. MD and RD values increased in both groups after radiosurgery. There was a negative correlation between pre-treatment FA, RD, and MD values after radiosurgery. Conclusion: Detection of low FA values due to the poor fiber content in meningioma before radiosurgery may be a guide in predicting the response to treatment. Further studies are required to have a better understanding of the relationship between pre- and post-treatment follow-up FA values and tumor volume in determining the efficacy of GKR in patients with meningioma.Publication Open Access Glioblastoma Stem Cells and Comparison of Isolation Methods.(2019-06-01) Kaynar, MY; Dundar, TOLGA TURAN; Hatiboglu, MA; Ergul, Z; Sozen, E; Seyithanoglu, MH; Tuzgen, S; Karaoz, E; DÜNDAR, TOLGA TURAN; HATİBOĞLU, MUSTAFA AZİZ; SEYİTHANOĞLU, MEHMET HAKANBackground: Glioblastoma (GBM) is the most aggressive and the most common primary brain tumor. Over the last few years, studies have identified many genetical and phenotypical molecular situations for developing new treatment modalities in patients with GBM. Nevertheless, main problem for the GBM is radio-chemotherapy resistance and relapse after the surgery. The identification of glioma stem cells and microenvironmental influences has created a paradigm shift in targets of therapy. Current studies have shown that glioma stem cell is responsible for aggressiveness, recurrence and resistance to therapy of GBM. GBM stem cell isolated from human GBM multiforme fresh tissue samples is important both for curative therapeutic options and personalized targeted therapy. The purpose of this study was to determine the most suitable isolation method of GBM stem cells (GSCs). Methods: Tumor tissue sample was obtained during the surgical resection of lesion in patients with the diagnosis of GBM. Tumor stem cell isolation from tissue was performed in three different ways: 1) GBM cell isolation with trypsin; 2) GBM cell isolation with brain tumor dissociation Kit (BTD Kit); and 3) GBM cell isolation with tumor dissociation enzyme (TDE). Results: We showed that GSCs were isolated from tumor specimen using flow cytometry and immunofluorescence staining. Our study showed that isolation with BTD Kit is the most suitable method to isolate GBM tissue-derived glial tumor stem cells. Conclusions: The development of alternative personalized therapies targeting brain tumor stem cell is urgently needed. It is important to understand the fundamental mechanisms of driving stem cells. If their life cycle mechanisms can be identified, we can control the growth of GBM.Publication Open Access Pituitary carcinomas: Rare and challenging(2019-08-01T00:00:00Z) Sinclair, Georges; Olsson, Martin; Benmakhlouf, Hamza; Alsaffar, Yahya; Ohnstone, Philippa; HATİBOĞLU, MUSTAFA AZİZ; Shamikh, Alia; HATİBOĞLU, MUSTAFA AZİZBackground: Pituitary carcinomas (PCs) are defined as adenohypophyseal tumors with metastatic activity within and outside the boundaries of the central nervous system (CNS). The condition is rare and therefore seldom reported; most lesions are hormone producing and have a tendency for complex evolution. As such, the management of PCs remains difficult. We present an illustrative case of PC with a brief review of the recent medical literature. Case Description: A 58-year-old patient was diagnosed with prolactinoma in 2005. The ensuing biochemical and radiological evolution proved contentious; local tumor control was never fully achieved despite multimodal management including pharmacological treatment, repeated resections, and radiotherapy. In late 2017, the patient developed metastatic lesions within the confinements of the CNS requiring further surgical interventions, high-dose radiation, and systemic treatment. Conclusion: As it was the case in our patient, PCs require tailored, multimodal treatments according to the degree of infiltration, site of invasion, and hormone status. Further studies are necessary to understand the mechanisms promoting “extra-sellar” activity, particularly at distant sites; the identification of biomarkers exposing the risk of PC remains a crucial aspect of diagnostics, prevention and future customized therapies.