@article{ZimmermannRichterWeicketal.2022,
  author    = {Zimmermann, Marcus and Richter, Anne and Weick, Stefan and Exner, Florian and Mantel, Frederick and Diefenhardt, Markus and Fokas, Emmanouil and Kosmala, Rebekka and Flentje, Michael and Polat, B{\"u}lent},
  title     = {Acute toxicities of patients with locally advanced rectal cancer treated with intensified chemoradiotherapy within the CAO/ARO/AIO-12 trial: comparing conventional versus VMAT planning at a single center},
  series = {Scientific Reports},
  volume    = {12},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-022-25647-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301255},
  year      = {2022},
  abstract  = {In locally advanced rectal cancer (LARC) neoadjuvant chemoradiotherapy is regarded as standard treatment. We assessed acute toxicities in patients receiving conventional 3D-conformal radiotherapy (3D-RT) and correlated them with dosimetric parameters after re-planning with volumetric modulated arc therapy (VMAT). Patients were randomized within the multicenter CAO/ARO/AIO-12 trial and received 50.4 Gy in 28 fractions and simultaneous chemotherapy with fluorouracil and oxaliplatin. Organs at risk (OAR) were contoured in a standardized approach. Acute toxicities and dose volume histogram parameters of 3D-RT plans were compared to retrospectively calculated VMAT plans. From 08/2015 to 01/2018, 35 patients with LARC were treated at one study center. Thirty-four patients were analyzed of whom 1 (3\%) was UICC stage II and 33 (97\%) patients were UICC stage III. Grade 3 acute toxicities occurred in 5 patients (15\%). Patients with acute grade 1 cystitis (n = 9) had significantly higher D\(_{mean}\) values for bladder (29.4 Gy vs. 25.2 Gy, p < 0.01) compared to patients without bladder toxicities. Acute diarrhea was associated with small bowel volume (grade 2: 870.1 ccm vs. grade 0-1: 647.3 ccm; p < 0.01) and with the irradiated volumes V5 to V50. Using VMAT planning, we could reduce mean doses and irradiated volumes for all OAR: D\(_{mean}\) bladder (21.9 Gy vs. 26.3 Gy, p < 0.01), small bowel volumes V5-V45 (p < 0.01), D\(_{mean}\) anal sphincter (34.6 Gy vs. 35.6 Gy, p < 0.01) and D\(_{mean}\) femoral heads (right 11.4 Gy vs. 25.9 Gy, left 12.5 Gy vs. 26.6 Gy, p < 0.01). Acute small bowel and bladder toxicities were dose and volume dependent. Dose and volume sparing for all OAR could be achieved through VMAT planning and might result in less acute toxicities.},
  language  = {en}
}
@article{KroeberWengerSchwegleretal.2015,
  author    = {Kroeber, Jana and Wenger, Barbara and Schwegler, Manuela and Daniel, Christoph and Schmidt, Manfred and Djuzenova, Cholpon S and Polat, B{\"u}lent and Flentje, Michael and Fietkau, Rainer and Distel, Luitpold V.},
  title     = {Distinct increased outliers among 136 rectal cancer patients assessed by \(\gamma\)H2AX},
  series = {Radiation Oncology},
  volume    = {10},
  journal   = {Radiation Oncology},
  number    = {36},
  doi       = {10.1186/s13014-015-0344-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144085},
  year      = {2015},
  abstract  = {Background: In recent years attention has focused on \(\gamma\)H2AX as a very sensitive double strand break indicator. It has been suggested that \(\gamma\)H2AX might be able to predict individual radiosensitivity. Our aim was to study the induction and repair of DNA double strand breaks labelled by \(\gamma\)H2AX in a large cohort. Methods: In a prospective study lymphocytes of 136 rectal cancer (RC) patients and 59 healthy individuals were ex vivo irradiated (IR) and initial DNA damage was compared to remaining DNA damage after 2 Gy and 24 hours repair time and preexisting DNA damage in unirradiated lymphocytes. Lymphocytes were immunostained with anti-\(\gamma\)H2AX antibodies and microscopic images with an extended depth of field were acquired. \(\gamma\)H2AX foci counting was performed using a semi-automatic image analysis software. Results: Distinct increased values of preexisting and remaining \(\gamma\)H2AX foci in the group of RC patients were found compared to the healthy individuals. Additionally there are clear differences within the groups and there are outliers in about 12\% of the RC patients after ex vivo IR. Conclusions: The \(\gamma\)H2AX assay has the capability to identify a group of outliers which are most probably patients with increased radiosensitivity having the highest risk of suffering radiotherapy-related late sequelae.},
  language  = {en}
}
@article{LisowskiTroemelLutyjetal.2022,
  author    = {Lisowski, Dominik and Tr{\"o}mel, Jannik and Lutyj, Paul and Lewitzki, Victor and Hartrampf, Philipp E. and Polat, B{\"u}lent and Flentje, Michael and Tamihardja, J{\"o}rg},
  title     = {Health-related quality of life and clinical outcome after radiotherapy of patients with intracranial meningioma},
  series = {Scientific Reports},
  volume    = {12},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-022-24192-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301233},
  year      = {2022},
  abstract  = {This retrospective, single-institutional study investigated long-term outcome, toxicity and health-related quality of life (HRQoL) in meningioma patients after radiotherapy. We analyzed the data of 119 patients who received radiotherapy at our department from 1997 to 2014 for intracranial WHO grade I-III meningioma. Fractionated stereotactic radiotherapy (FSRT), intensity modulated radiotherapy (IMRT) or radiosurgery radiation was applied. The EORTC QLQ-C30 and QLQ-BN20 questionnaires were completed for assessment of HRQoL. Overall survival (OS) for the entire study group was 89.6\% at 5 years and 75.9\% at 10 years. Local control (LC) at 5 and 10 years was 82.4\% and 73.4\%, respectively. Local recurrence was observed in 22 patients (18.5\%). Higher grade acute and chronic toxicities were observed in seven patients (5.9\%) and five patients (4.2\%), respectively. Global health status was rated with a mean of 59.9 points (SD 22.3) on QLQ-C30. In conclusion, radiotherapy resulted in very good long-term survival and tumor control rates with low rates of severe toxicities but with a deterioration of long-term HRQoL.},
  language  = {en}
}
@article{SaidPolatSteinetal.2012,
  author    = {Said, Harun M. and Polat, Buelent and Stein, Susanne and Guckenberger, Mathias and Hagemann, Carsten and Staab, Adrian and Katzer, Astrid and Anacker, Jelena and Flentje, Michael and Vordermark, Dirk},
  title     = {Inhibition of N-Myc down regulated gene 1 in in vitro cultured human glioblastoma cells},
  series = {World Journal of Clinical Oncology},
  volume    = {3},
  journal   = {World Journal of Clinical Oncology},
  number    = {7},
  doi       = {10.5306/wjco.v3.i7.104},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123385},
  pages     = {104-110},
  year      = {2012},
  abstract  = {AIM: To study short dsRNA oligonucleotides (siRNA) as a potent tool for artificially modulating gene expression of N-Myc down regulated gene 1 (NDRG1) gene induced under different physiological conditions (Normoxia and hypoxia) modulating NDRG1 transcription, mRNA stability and translation. METHODS: A cell line established from a patient with glioblastoma multiforme. Plasmid DNA for transfections was prepared with the Endofree Plasmid Maxi kit. From plates containing 5 x 10(7) cells, nuclear extracts were prepared according to previous protocols. The pSUPER-NDRG1 vectors were designed, two sequences were selected from the human NDRG1 cDNA (5'-GCATTATTGGCATGGGAAC-3' and 5'-ATGCAGAGTAACGTGGAAG-3'. reverse transcription polymerase chain reaction was performed using primers designed using published information on -actin and hypoxia-inducible factor (HIF)-1 mRNA sequences in GenBank. NDRG1 mRNA and protein level expression results under different conditions of hypoxia or reoxygenation were compared to aerobic control conditions using the Mann-Whitney U test. Reoxygenation values were also compared to the NDRG1 levels after 24 h of hypoxia (P < 0.05 was considered significant). RESULTS: siRNA- and iodoacetate (IAA)-mediated downregulation of NDRG1 mRNA and protein expression in vitro in human glioblastoma cell lines showed a nearly complete inhibition of NDRG1 expression when compared to the results obtained due to the inhibitory role of glycolysis inhibitor IAA. Hypoxia responsive elements bound by nuclear HIF-1 in human glioblastoma cells in vitro under different oxygenation conditions and the clearly enhanced binding of nuclear extracts from glioblastoma cell samples exposed to extreme hypoxic conditions confirmed the HIF-1 Western blotting results. CONCLUSION: NDRG1 represents an additional diagnostic marker for brain tumor detection, due to the role of hypoxia in regulating this gene, and it can represent a potential target for tumor treatment in human glioblastoma. The siRNA method can represent an elegant alternative to modulate the expression of the hypoxia induced NDRG1 gene and can help to monitor the development of the cancer disease treatment outcome through monitoring the expression of this gene in the patients undergoing the different therapeutic treatment alternatives available nowadays.},
  language  = {en}
}
@article{FischerHartmannReisslandetal.2022,
  author    = {Fischer, Thomas and Hartmann, Oliver and Reissland, Michaela and Prieto-Garcia, Cristian and Klann, Kevin and Pahor, Nikolett and Sch{\"u}lein-V{\"o}lk, Christina and Baluapuri, Apoorva and Polat, B{\"u}lent and Abazari, Arya and Gerhard-Hartmann, Elena and Kopp, Hans-Georg and Essmann, Frank and Rosenfeldt, Mathias and M{\"u}nch, Christian and Flentje, Michael and Diefenbacher, Markus E.},
  title     = {PTEN mutant non-small cell lung cancer require ATM to suppress pro-apoptotic signalling and evade radiotherapy},
  series = {Cell \& Bioscience},
  volume    = {12},
  journal   = {Cell \& Bioscience},
  issn      = {2045-3701},
  doi       = {10.1186/s13578-022-00778-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299865},
  year      = {2022},
  abstract  = {Background Despite advances in treatment of patients with non-small cell lung cancer, carriers of certain genetic alterations are prone to failure. One such factor frequently mutated, is the tumor suppressor PTEN. These tumors are supposed to be more resistant to radiation, chemo- and immunotherapy. Results We demonstrate that loss of PTEN led to altered expression of transcriptional programs which directly regulate therapy resistance, resulting in establishment of radiation resistance. While PTEN-deficient tumor cells were not dependent on DNA-PK for IR resistance nor activated ATR during IR, they showed a significant dependence for the DNA damage kinase ATM. Pharmacologic inhibition of ATM, via KU-60019 and AZD1390 at non-toxic doses, restored and even synergized with IR in PTEN-deficient human and murine NSCLC cells as well in a multicellular organotypic ex vivo tumor model. Conclusion PTEN tumors are addicted to ATM to detect and repair radiation induced DNA damage. This creates an exploitable bottleneck. At least in cellulo and ex vivo we show that low concentration of ATM inhibitor is able to synergise with IR to treat PTEN-deficient tumors in genetically well-defined IR resistant lung cancer models.},
  language  = {en}
}
@article{TamihardjaLutyjKraftetal.2021,
  author    = {Tamihardja, J{\"o}rg and Lutyj, Paul and Kraft, Johannes and Lisowski, Dominik and Weick, Stefan and Flentje, Michael and Polat, B{\"u}lent},
  title     = {Two-Weekly High-Dose-Rate Brachytherapy Boost After External Beam Radiotherapy for Localized Prostate Cancer: Long-Term Outcome and Toxicity Analysis},
  series = {Frontiers in Oncology},
  volume    = {11},
  journal   = {Frontiers in Oncology},
  issn      = {2234-943X},
  doi       = {10.3389/fonc.2021.764536},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250992},
  year      = {2021},
  abstract  = {Purpose Evaluation of clinical outcome of two-weekly high-dose-rate brachytherapy boost after external beam radiotherapy (EBRT) for localized prostate cancer. Methods 338 patients with localized prostate cancer receiving definitive EBRT followed by a two-weekly high-dose-rate brachytherapy boost (HDR-BT boost) in the period of 2002 to 2019 were analyzed. EBRT, delivered in 46 Gy (DMean) in conventional fractionation, was followed by two fractions HDR-BT boost with 9 Gy (D90\%) two and four weeks after EBRT. Androgen deprivation therapy (ADT) was added in 176 (52.1\%) patients. Genitourinary (GU)/gastrointestinal (GI) toxicity was evaluated utilizing the Common Toxicity Criteria for Adverse Events (version 5.0) and biochemical failure was defined according to the Phoenix definition. Results Median follow-up was 101.8 months. 15 (4.4\%)/115 (34.0\%)/208 (61.5\%) patients had low-/intermediate-/high-risk cancer according to the D`Amico risk classification. Estimated 5-year and 10-year biochemical relapse-free survival (bRFS) was 84.7\% and 75.9\% for all patients. The estimated 5-year bRFS was 93.3\%, 93.4\% and 79.5\% for low-, intermediate- and high-risk disease, respectively. The estimated 10-year freedom from distant metastasis (FFM) and overall survival (OS) rates were 86.5\% and 70.0\%. Cumulative 5-year late GU toxicity and late GI toxicity grade ≥ 2 was observed in 19.3\% and 5.0\% of the patients, respectively. Cumulative 5-year late grade 3 GU/GI toxicity occurred in 3.6\%/0.3\%. Conclusions Two-weekly HDR-BT boost after EBRT for localized prostate cancer showed an excellent toxicity profile with low GU/GI toxicity rates and effective long-term biochemical control.},
  language  = {en}
}