Araştırma Çıktıları
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Item New horizons from novel therapies in malignant pleural mesothelioma(VIA MEDICA, 2020-01-01) Sayan, Mutlay; Mamidanna, Swati; Eren, Mehmet Fuat; Daliparty, Vasudev; Mustafayev, Teuta Zoto; Nelson, Carl; Ohri, Nisha; Jabbour, Salma K.; Mert, Aslihan Guven; Atalar, BanuMalignant pleural mesothelioma (MPM) is a relatively rare, but highly lethal cancer of the pleural mesothelial cells. Its pathogenesis is integrally linked to asbestos exposure. In spite of recent developments providing a more detailed understanding of the pathogenesis, the outcomes continue to be poor. To date, trimodality therapy involving surgery coupled with chemotherapy and/or radiotherapy remains the standard of therapy. The development of resistance of the tumor cells to radiation and several chemotherapeutic agents poses even greater challenges in the management of this cancer. Ionizing radiation damages cancer cell DNA and aids in therapeutic response, but it also activates cell survival signaling pathways that helps the tumor cells to overcome radiation-induced cytotoxicity. A careful evaluation of the biology involved in mesothelioma with an emphasis on the workings of pro-survival signaling pathways might offer some guidance for treatment options. This review focuses on the existing treatment options for MPM, novel treatment approaches based on recent studies combining the use of inhibitors which target different pro-survival pathways, and radiotherapy to optimize treatment.Item Magnetic resonance image-guided adaptive stereotactic body radiotherapy for prostate cancer: preliminary results of outcome and toxicity(BRITISH INST RADIOLOGY, 2021-01-01) Ugurluer, Gamze; Atalar, Banu; Mustafayev, Teuta Zoto; Gungor, Gorkem; Aydin, Gokhan; Sengoz, Meric; Abacioglu, Ufuk; Tuna, Mustafa Bilal; Kural, Ali Riza; Ozyar, EnisObjective: Using moderate or ultra-hypofractionation, which is also known as stereotactic body radiotherapy (SBRT) for treatment of localized prostate cancer patients has been increased. We present our preliminary results on the clinical utilization of MRI-guided adaptive radiotherapy (MRgRT) for prostate cancer patients with the workflow, dosimetric parameters, toxicities and prostate-specific antigen (PSA) response. Methods: 50 prostate cancer patients treated with ultrahypofractionation were included in the study. Treatment was performed with intensity-modulated radiation therapy (step and shoot) technique and daily plan adaptation using MRgRT. The SBRT consisted of 36.25 Gy in 5 fractions with a 7.25 Gy fraction size. The time for workflow steps was documented. Patients were followed for the acute and late toxicities and PSA response. Results: The median follow-up for our cohort was 10 months (range between 3 and 29 months). The median age was 73.5 years (range between 50 and 84 years). MRgRT was well tolerated by all patients. Acute genitourinary (GU) toxicity rate of Grade 1 and Grade 2 was 28 and 36\%, respectively. Only 6\% of patients had acute Grade 1 gastrointestinal (GI) toxicity and there was no Grade 2G1 toxicity. To date, late Grade 1 GU toxicity was experienced by 24\% of patients, 2\% of patients experienced Grade 2 GU toxicity and 6\% of patients reported Grade 2 GI toxicity. Due to the short follow-up, PSA nadir has not been reached yet in our cohort. Conclusion: In conclusion, MRgRT represents a new method for delivering SBRT with markerless soft tissue visualization, online adaptive planning and real-time tracking. Our study suggests that ultra-hypofractionation has an acceptable acute and very low late toxicity profile. Advances in knowledge: MRgRT represents a new markerless method for delivering SBRT for localized prostate cancer providing online adaptive planning and real-time tracking and acute and late toxicity profile is acceptable.Item Output factors of ionization chambers and solid state detectors for mobile intraoperative radiotherapy (IORT) accelerator electron beams(WILEY, 2019-01-01) Gungor, Goerkem; Aydin, Gokhan; Mustafayev, Teuta Zoto; Ozyar, EnisPurpose The electron energy characteristics of mobile intraoperative radiotherapy (IORT) accelerator LIAC((R)) differ from commonly used linear accelerators, thus some of the frequently used detectors can give less accurate results. The aim of this study is to evaluate the output factors (OFs) of several ionization chambers (IC) and solid state detectors (SS) for electron beam energies generated by LIAC((R)) and compare with the output factor of Monte Carlo model (MC) in order to determine the adequate detectors for LIAC((R)). Methods The OFs were measured for 6, 8, 10, and 12 MeV electron energies with PTW 23343 Markus, PTW 34045 Advanced Markus, PTW 34001 Roos, IBA PPC05, IBA PPC40, IBA NACP-02, PTW 31010 Semiflex, PTW 31021 Semiflex 3D, PTW 31014 Pinpoint, PTW 60017 Diode E, PTW 60018 Diode SRS, SNC Diode EDGE, and PTW 60019 micro Diamond detectors. Ion recombination factors (k(sat)) of IC were measured for all applicator sizes and OFs were corrected according to k(sat). The measured OFs were compared with Monte Carlo output factors (OFMC). Results The measured OFs of IBA PPC05, PTW Advanced Markus, PTW Pinpoint, PTW microDiamond, and PTW Diode E detectors are in good agreement with OFMC. The maximum deviations of IBA PPC05 OFs to OFMC are -1.6\%, +1.5\%, +1.5\%, and +2.0\%