Sebastian Graf

Dr. Sebastian Graf

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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28 October 2020 in Journal of Clinical Medicine
Verified
Journal Article
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DLDavid Lang
David Lang
GWGerald Wahl
Gerald Wahl
NPNikolaus Poier
Nikolaus Poier
SGSebastian Graf
Sebastian Graf
DKDavid Kiesl
David Kiesl
MGMichael Gabriel
Michael Gabriel
Cancer immunotherapy using immune-checkpoint inhibitors (ICI) has revolutionized the therapeutic landscape of various malignancies like non-small-cell lung cancer or melanoma. Pre-therapy response prediction and assessment during ICI treatment is challenging due to the lack of reliable biomarkers and the possibility of atypical radiological response patterns. Positron emission tomography/computed tomography (PET/CT) enables the visualization and quantification of metabolic lesion activity additional to conventional CT imaging. Various biomarkers derived from PET/CT have been reported as predictors for response to ICI and may aid to overcome the challenges clinicians currently face in the management of ICI-treated patients. In this narrative review, experts in nuclear medicine, thoracic oncology, dermatooncology, hemato- and internal oncology, urological and head/neck tumors performed literature reviews in their respective field and a joint discussion on the use of PET/CT in the context of ICI treatment. The aims were to give a clinical overview on present standards and evidence, to identify current challenges and fields of research and to enable an outlook to future developments and their possible implications. Multiple promising studies concerning ICI response assessment or prediction using biomarkers derived from PET/CT alone or as composite biomarkers have been identified for various malignancies and disease stages. Of interest, additional major incentives in the field may evolve from novel tracers specifically targeting immune-checkpoint molecules which could allow not only response assessment and prognosis, but also visualization of histological tumor cell properties like programmed death-ligand (PD-L1) expression in vivo. Despite the broad range of existing literature on PET/CT-derived biomarkers in ICI therapy, implications for daily clinical practice remain elusive. High-quality prospective data are urgently warranted to determine whether patients benefit from the application of PET/CT in terms of prognosis. At the moment, the lack of such evidence as well as the absence of standardized imaging methods and biomarkers still precludes PET/CT imaging to be included in the relevant clinical practice guidelines.

3 March 2021 in Der Urologe
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Journal Article
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SGSebastian Graf
Sebastian Graf
JKJ. Kranz
J. Kranz
SSS. Schmidt
S. Schmidt
LBL. Bellut
L. Bellut
AUA. Uhlig
A. Uhlig
Zusammenfassung: Der vorliegende Beitrag gibt einen Überblick über die verschiedenen Arten von Reviews (Übersichtsarbeiten) als Formen der Evidenzsynthese mit besonderem Hinblick auf deren Stärken sowie Limitationen. Reviews können Wissen in aggregierter Form beschreiben und erlauben zusätzlich eine Bewertung der Studienqualität eingeschlossener Arbeiten. Die Aussagekraft bzw. die Vertrauenswürdigkeit der Ergebnisse eines Reviews hängt stark von der Qualität der eingeschlossenen Daten ab, weswegen eine konsequente Auswahlstrategie notwendig ist. Ein Basiswissen zur Literaturbewertung und zu möglichen Verzerrungseffekten ist auch in der Betrachtung von Übersichtsarbeiten notwendig. Zu diesem Zweck werden in diesem Artikel auch ausgewählte Werkzeuge zur Evidenzbewertung und zur Beurteilung des Biasrisikos vorgestellt.

27 October 2021 in Cancers
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GTGennadi Tulchiner
Gennadi Tulchiner
NSNina Staudacher
Nina Staudacher
JFJosef Fritz
Josef Fritz
MHMonika Hackl
Monika Hackl
MPMartin Pichler
Martin Pichler
Renate PichlerRenate Pichler
Renate Pichler
We conducted a retrospective National Cancer Registry study in Austria to assess a possible seasonal variation in the clinical diagnosis of testicular germ cell tumors (TGCT). In total, 3615 testicular cancer diagnoses were identified during an 11-year period from 2008 to 2018. Rate ratios for the monthly number of TGCT diagnoses, as well as of seasons and half-years, were assessed using a quasi-Poisson model. We identified, for the first time, a statistically significant seasonal trend (p < 0.001) in the frequency of monthly newly diagnosed cases of TGCT. In detail, clear seasonal variations with a reduction in the tumor incidence during the summer months (Apr–Sep) and an increase during the winter months (Oct–Mar) were observed (p < 0.001). Focusing on seasonality, the incidence during the months of Oct–Dec (p = 0.008) and Jan–Mar (p < 0.001) was significantly higher compared to the months of Jul–Sep, respectively. Regarding histopathological features, there is a predominating incidence in the winter months compared to summer months, mainly concerning pure seminomas (p < 0.001), but not the non-seminoma or mixed TGCT groups. In conclusion, the incidence of TGCT diagnoses in Austria has a strong seasonal pattern, with the highest rate during the winter months. These findings may be explained by a delay of self-referral during the summer months. However, the hypothetical influence of vitamin D3 in testicular carcinogenesis underlying seasonal changes in TGCT diagnosis should be the focus of further research.

20 April 2023 in Journal of Cancer Research and Clinical Oncology
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LSLaila Schneidewind
Laila Schneidewind
BKBernhard Kiss
Bernhard Kiss
FZFriedemann Zengerling
Friedemann Zengerling
ABAngelika Borkowetz
Angelika Borkowetz
SGSebastian Graf
Sebastian Graf
AUAnnemarie Uhlig
Annemarie Uhlig
Purpose: To analyze gender-specific differences in survival parameters in advanced or metastatic urothelial cancer patients undergoing immune checkpoint inhibition. Methods: The primary aim of this systematic review and meta-analysis was to evaluate gender-specific differences in disease-free (DFS), progression-free (PFS), cancer-specific survival (CSS), event-free survival (EFS), overall survival (OS) and objective response rate (ORR). The sources MEDLINE, Embase and Cochrane Library were systematically searched from January 2010 to June 2022. No restrictions were made concerning language, study region or publication type. A comparison of gender-specific differences in survival parameters was performed using a random-effects meta-analysis. A risk of bias assessment was done using the ROBINS-I tool. Results: Five studies were included. In a random-effect meta-analysis of the studies, PCD4989g and IMvigor 211 with both using atezolizumab, females were more likely to have better objective response rate (ORR) than men (OR 2.24; 95% CI 1.20–4.16; p = 0.0110). In addition, females had a comparable median OS to men (MD 1.16; 95% CI − 3.15–5.46; p = 0.598). In summary, comparing all results, a tendency was seen toward better response rates and survival parameters in female patients. The risk of bias assessment yielded an overall low risk of bias. Conclusions: There is a tendency toward better outcomes in women for immunotherapy in advanced or metastatic urothelial cancer, but only for the antibody atezolizumab women have a significantly better ORR. Unfortunately, many studies fail to report gender-specific outcomes. Therefore, further research is essential when aiming for individualized medicine. This research should address immunological confounders.

23 July 2022 in Cancers
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SDSusanne Deininger
Susanne Deininger
Lukas LusuardiLukas Lusuardi
Lukas Lusuardi
MPMaximilian Pallauf
Maximilian Pallauf
SHStefan Hecht
Stefan Hecht
RFRosemarie Forstner
Rosemarie Forstner
PTPeter Törzsök
Peter Törzsök
Background: The purpose of this study was to retrospectively analyze the diagnostic accuracy of magnetic resonance imaging (MRI) examinations of the scrotum in comparison with standard ultrasound (US) and histopathology. Methods: A retrospective multi-center analysis of MRI examinations of the scrotum performed between 06/2008 and 04/2021 was conducted. Results: A total of n = 113 patients were included. A total of 53 histopathologies were available, with 52.8% malignant and 50.9% benign findings. Related to histopathology, imaging was true negative, false negative, false positive, and true positive in 4.1%, 2.1%, 25.0% and 37.5% for standard ultrasound (US) and 9.1%, 1.8%, 25.5% and 43.6% for MRI. Sensitivity, specificity, positive predictive value and negative predictive value were 94.7%, 20.0%, 36.0% and 88.9% for US and 85.7%, 72.8%, 52.1% and 93.7% for MRI, respectively. Benign lesions were significantly smaller than malignant ones in standard US (p = 0.001), histopathology (p = 0.001) and MRI (p = 0.004). The size of malignant tumors did not differ significantly between histopathology and standard US (0.72) and between histopathology and MRI (p = 0.88). Conclusions: MRI shows good sensitivity and specificity for the estimation of testicular tumors in this collective. Benign lesions are significantly smaller than malignant ones. Both MRI and US can estimate the size of malignant tumors adequately.

19 September 2023 in Current Opinion in Urology
Verified
Journal Article
Closed access
SGSebastian Graf
Sebastian Graf
BSBhaskar K. Somani
Bhaskar K. Somani
Purpose of review: Management of stone disease in pregnancy poses a challenge for all healthcare professionals involved in their care. During pregnancy, there is an increase in the incidence of urolithiasis. Major technological and procedural advances have been seen in the last decade for endoscopic management of urolithiasis. The purpose of this review is to provide a comprehensive workup of available literature on use of ureteroscopy for stone treatment during pregnancy. Recent findings: We identified 268 articles on screening, of which 28 were included in the final review. Overall adverse event rates were low, with no severe complications reported in the included studies. On multivariate analysis, the only significant correlation was an inverse relationship between calculated caseload and adverse obstetric events. No further correlation could be found between caseload, operation technique and adverse event rates. Data quality was low among the included studies. Summary: While ureteroscopy is a relatively safe and effective option for active stone treatment during pregnancy, they should be performed in experienced endourology centres in conjunction with obstetric teams.