Natalia Kremenevski

Dr. Natalia Kremenevski

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 June 2020 in Neuroendocrinology
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Journal Article
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NKNatalia Kremenevski
Natalia Kremenevski
SSSven-Martin Schlaffer
Sven-Martin Schlaffer
RCRoland Coras
Roland Coras
TKThomas M Kinfe
Thomas M Kinfe
TGThomas Graillon
Thomas Graillon
MBMichael Buchfelder
Michael Buchfelder
Skull base chordomas account for less than 0.2% and chondrosarcomas for less than 0.15% of all intracranial tumors. Although their clinical and imaging presentations are similar, they derive from different origins. Chordomas arise from embryonic remnants of the primitive notochord and chondrosarcomas from primitive mesenchymal cells or from the embryonic rest of the cranial cartilaginous matrix. Both entities are characterized by infiltration and destruction of the surrounding bone and soft tissue and a high locoregional recurrence rate. Chondrosarcomas, when treated with similar complex strategies, display a much better prognosis than chordomas. The overall survival is approximately 65% for chordomas and 80% for chondrosarcomas at 5 years and 30 and 50%, respectively, at 10 years. Chordomas are divided into the following 3 histological types: classical (conventional), chondroid, and dedifferentiated. Chondrosarcomas have conventional, mesenchymal, clear cell, and dedifferentiated subgroups. Both tumor entities often present with nonspecific symptoms, and headaches are the most reported initial symptom. Computed tomography and magnetic resonance imaging are required to determine the tumor localization and the extent of tumor growth. The treatment philosophy is to maximize tumor resection, minimize morbidity, and preserve function. Neurosurgical approaches commonly used for the resection of intracranial chordomas and chondrosarcomas are transsphenoidal, transbasal, cranio-orbitozygomatic, transzygomatic extended middle fossa, transcondylar, and transmaxillary approaches. Chordomas and chondrosarcomas are not sensitive to chemotherapy and there are no approved drugs for their treatment. The present treatment concept is a combination of surgical resection with a maximal excision and preserving patients’ quality of life by adjuvant radiotherapy for both chordomas and chondrosarcomas.

10 April 2023 in Current Oncology Reports
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Journal Article
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NKNatalia Kremenevski
Natalia Kremenevski
MBMichael Buchfelder
Michael Buchfelder
NHNirjhar Hore
Nirjhar Hore
Purpose of Review: Intracranial germinomas constitute a rare brain tumor entity of unknown etiology, characterized by unique histopathology and molecular biology. In this manuscript, we review the literature focusing on the epidemiology, histopathology with molecular biology, clinical presentation with emphasis on tumor location, diagnostic workup, and current treatment strategies with related clinical outcomes of intracranial germinomas. Recent Findings: Although the optimal treatment strategy remains a matter of debate, intracranial germinomas respond well to radiotherapy, chemotherapy, or a combination of both and are characterized by very high cure and survival rates. It is well-known that early discrimination of germinomas from other intracranial neoplasms facilitates the timely initiation of appropriate treatment, thereby contributing to the reduction of morbidity as well as mortality. Summary: Ongoing research will need to be directed towards discovering and refining reliable parameters for early diagnosis and evaluation of prognosis in patients with intracranial germinomas.

23 April 2021 in Molecular Imaging and Biology
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EHElisabeth Heynold
Elisabeth Heynold
MZMax Zimmermann
Max Zimmermann
NHNirjhar Hore
Nirjhar Hore
MBMichael Buchfelder
Michael Buchfelder
ADArnd Doerfler
Arnd Doerfler
NKNatalia Kremenevski
Natalia Kremenevski
Purpose: Glioblastomas (GB) and solitary brain metastases (BM) are the most common brain tumors in adults. GB and BM may appear similar in conventional magnetic resonance imaging (cMRI). Their management strategies, however, are quite different with significant consequences on clinical outcome. The aim of this study was to evaluate the usefulness of a previously presented physiological MRI approach scoping to obtain quantitative information about microvascular architecture and perfusion, neovascularization activity, and oxygen metabolism to differentiate GB from BM. Procedures: Thirty-three consecutive patients with newly diagnosed, untreated, and histopathologically confirmed GB or BM were preoperatively examined with our physiological MRI approach as part of the cMRI protocol. Results: Physiological MRI biomarker maps revealed several significant differences in the pathophysiology of GB and BM: Central necrosis was more hypoxic in GB than in BM (30 %; P = 0.036), which was associated with higher neovascularization activity (65 %; P = 0.043) and metabolic rate of oxygen (48 %; P = 0.004) in the adjacent contrast-enhancing viable tumor parts of GB. In peritumoral edema, GB infiltration caused neovascularization activity (93 %; P = 0.018) and higher microvascular perfusion (30 %; P = 0.022) associated with higher tissue oxygen tension (33 %; P = 0.020) and lower oxygen extraction from vasculature (32 %; P = 0.040). Conclusion: Our physiological MRI approach, which requires only 7 min of extra data acquisition time, might be helpful to noninvasively distinguish GB and BM based on pathophysiological differences. However, further studies including more patients are required.

5 April 2025 in Pituitary
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Journal Article
Open access
NKNatalia Kremenevski
Natalia Kremenevski
OSOliver Schnell
Oliver Schnell
RCRoland Coras
Roland Coras
MBMichael Buchfelder
Michael Buchfelder
NHNirjhar Hore
Nirjhar Hore
Purpose: This study evaluates the clinical presentation, endocrine dysfunction, surgical outcome, and long-term prognosis in patients with histologically confirmed posterior pituitary tumors (PPTs). Methods: A retrospective cohort study was conducted on 19 patients treated for PPTs at a single center between 2000 and 2023. Data on clinical, endocrine, and surgical outcomes were collected and analyzed. Results: The cohort included 3 pituicytomas (PCs), 8 granular cell tumors (GCTs), and 8 spindle cell oncocytomas (SCOs) patients, with a female predominance (58%) and a mean age of 57.2 ± 13.2 years. Symptoms leading to diagnosis were headache (31.6%), visual impairment (21%), and sexual dysfunction (10.5%). GCT patients had higher preoperative BMI (34.49 ± 5.72) compared to PC (22.12 ± 2.40) and SCO (24.74 ± 4.24) patients (p < 0.01). Postoperative BMI increased across all groups, with GCTs patients showing the steepest rise (p < 0.01). Endocrine dysfunction largely persisted or worsened after surgery, with limited recovery at follow-up. Surgical approaches included transsphenoidal (48%) and transcranial (52%), achieving gross total resection in 58% of cases. Tumor recurrence occurred in 16% of patients, all requiring adjuvant radiation therapy. Tumor-specific survival at 5 years was 100% with an overall survival rate of 80% where non-tumor-related comorbidities accounted for the observed mortality. Conclusion: PPTs are rare tumors with significant endocrine and metabolic consequences. While surgical management is associated with favorable tumor-specific survival, persistent endocrine dysfunction and postoperative progressive BMI underscore the need for long-term follow-up and targeted interventions. These findings contribute to the understanding of PPT biology and support the development of optimized management strategies.

9 April 2021 in Cancers
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Journal Article
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Andreas StadlbauerAndreas Stadlbauer
Andreas Stadlbauer
SOStefan Oberndorfer
Stefan Oberndorfer
GHGertraud Heinz
Gertraud Heinz
Max ZimmermannMax Zimmermann
Max Zimmermann
TKThomas M Kinfe
Thomas M Kinfe
FMFranz Marhold
Franz Marhold
Anaplastic gliomas (AG) represents aggressive brain tumors that often affect young adults. Although isocitrate-dehydrogenase (IDH) gene mutation has been identified as a more favorable prognostic factor, most IDH-mutated AG patients are confronted with tumor recurrence. Hence, increased knowledge about pathophysiological precursors of AG recurrence is urgently needed in order to develop precise diagnostic monitoring and tailored therapeutic approaches. In this study, 142 physiological magnetic resonance imaging (phyMRI) follow-up examinations in 60 AG patients after standard therapy were evaluated and magnetic resonance imaging (MRI) biomarker maps for microvascular architecture and perfusion, neovascularization activity, oxygen metabolism, and hypoxia calculated. From these 60 patients, 34 patients developed recurrence of the AG, and 26 patients showed no signs for AG recurrence during the study period. The time courses of MRI biomarker changes were analyzed regarding early pathophysiological alterations over a one-year period before radiological AG recurrence or a one-year period of stable disease for patients without recurrence, respectively. We detected intensifying local tissue hypoxia 250 days prior to radiological recurrence which initiated upregulation of neovascularization activity 50 to 70 days later. These changes were associated with a switch from an avascular infiltrative to a vascularized proliferative phenotype of the tumor cells another 30 days later. The dynamic changes of blood perfusion, microvessel density, neovascularization activity, and oxygen metabolism showed a close physiological interplay in the one-year period prior to radiological recurrence of IDH-mutated AG. These findings may path the wave for implementing both new MR-based imaging modalities for routine follow-up monitoring of AG patients after standard therapy and furthermore may support the development of novel, tailored therapy options in recurrent AG.