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Showing 6 results for Yilmaz
Dr. M. Izmirli, G. Yilmazer, T. Cakir, Z.a. Palabiyik, M. Nart,
Volume 14, Issue 3 (7-2016)
Abstract
Aims: It was aimed to investigate postoperative conformal radiotherapy planning that provides the best target volume and the least dose for critical organs in cancers of stomach. Methods: This study was conducted on the CT simulation images of thirty patients diagnosed with gastric cancer. Target volumes and the organs at risk were contoured. AP-PA reciprocal parallel field conventional plan and three- and four-field 3D conformal plans were created using linear accelerator. Target volumes and doses consumed by organs at risk were compared by dose-volume histograms. Results: While a sufficient dose could be applied to target volumes in all plans with conformal planning, average figures showed that 95% of porta hepatis area failed to take the prescribed dose (D95) in some plans by using AP-PA reciprocal parallel zone conventional plans. The most convenient protection for spinal cord, heart and kidneys was obtained by conformal four-field technique and the liver doses were increased in conformal four-field plans but did not exceed the tolerance dose. And also, in the conventional AP-PA reciprocal parallel field plans, tolerance dose of spinal cord (4500 cGy) was exceeded. Conclusion: In this study, conformal four-field technique was superior considering target volume dose distributions, and especially spinal cord doses in all localizations and heart doses in cardia tumors. Kidney doses were also reduced in conformal four-field planning, but failed to reach statistical significance. There was a not exceeding tolerance limits dose increase in liver
M.d., E. Kirsever, H.s. Kiziltan, R. Yilmaz,
Volume 20, Issue 1 (1-2022)
Abstract
Background: The side effects of therapies such as chemotherapy (CT), radiotherapy (RT) and surgery in cancer patients are very high. For this reason, even when recovery is achieved in cancer, life is often shortened due to the side effects of treatments. Bioresonance treatment (BRT) on cancer is intended to reduce cancer-related complaints such as pain, nausea and weakness or treatment side effects. Materials and Methods: In this study, BRT effects have been evaluated according to the performance status, symptomatic recovery after the therapy in cancer patients treated with the BICOM BRT with or without RT or CT. We used to Ai programs, harmonious inverted and disharmonious inverted (Hi-Di) programs for the treatment of, pain, nosea, dispnea etc. complaints with using local electrods of BICOM machine. Results: A statistically significant difference was found between the treatment response averages of BRT application groups according to ECOG performance (Eastern Cooperative Oncology Group performance) scale. It is understood that the BRT treatment response was obtained later sessions of the group wich have better scoring (p = 0.005). Conclusion: The treatment response of with worse ECOG performance scoring of patients was better in early sessions than late sessions of BRT. Whereas the response time was shorter than the late responding patients. BRT method decreased to side effets of conventional cancer therapies also increased to the quality of life and palliation of patients.
G. Seven Tuncer, Ph.d., H. Demir, M. Izmirli, T. Cakır, G. Yilmazer, C. Demir,
Volume 20, Issue 1 (1-2022)
Abstract
Background: We tried to reveal the relationship between the levels of some important minerals, rare elements and heavy metals by measuring serum cobalt (Co), lead (Pb), zinc (Zn), iron (Fe), copper (Cu), cadmium (Cd), magnesium (Mg), manganese (Mn), catalase (CAT) and carbonic anhydrase (CA) levels in head and neck, CNS, esophagus, stomach and breast cancers receiving radiotherapy. Materials and Methods: Serum Cu, Fe, Pb, Zn, Co, Mg, Mn and Cd levels were measured using atomic absorption spectrophotometry. Carbonic anhydrase activity (CA), CO2 hydration measurements were made using bromothymol blue method as indicator. Results: Catalase activity, carbonic anhydrase activity and serum copper, lead, zinc, iron, cobalt, cadmium, manganese, magnesium measurements for baseline and post-radiotherapy values differ greatly in cancer patients compared to healthy subjects (p<0.05). Conclusion: As a result, these findings have a significant impact on the pathophysiology of cancer. It can be argued that this paper shows a preliminary study for examining the effect of radiotherapy treatment on the activity of erythrocyte catalase, carbonic anhydrase and serum levels of cobalt, lead (Pb), zinc, iron, copper, cadmium, magnesium and manganese in the head and neck, CNS, stomach, esophagus and breast cancers receiving radiotherapy treatment.
Ph.d., T. Berber, I. Harmankaya, F. Aksaray, Y. Büyükpolat, F. Adatepe, B.d. Yilmaz, S.t. Dinçer, G. Coşgun, Ç. Numanoglu, M.n. Güven, M.e. Gül, C. Yildirim, A.a. Erken,
Volume 20, Issue 3 (7-2022)
Abstract
Background: To elucidate the efficacy and toxicity of brain re-radiotherapy for recurrent large inoperable gliomas using radiosurgery. Materials and Methods: Between 2014 and 2018, extreme hypofractionated radiosurgery was performed using Accuray’s Cyberknife® system on 14 lesions (12 patients) grade 4 recurrence lesions of 6 patients with anaplastic astrocytoma and 6 patients with glioblastoma who had previously undergone surgery and cranial radiotherapy and had a local-regional recurrence. Six patients (8 lesions) were given a biologic effective dose (BED10) of 48 Gy and lower, and six patients were given a BED10 of 59.5 Gy and higher. The Response Assessment in Neuro-Oncology Criteria (RANO) were used for tumor response, and the Common Terminology for Adverse Events (CTCAE) was used for adverse effect assessment. The primary endpoint was determined as overall survival, and first treatment and salvage treatment time. Results: The median age of the patients was 43 years, and the median Karnofsky Performance Status (KPS) was 70. The median time from the first radiotherapy to death was 34 months. The median time from the previous radiotherapy was 29.5 months (R:17-40). The median survival was 10 months for those with recurrence before 29.5 months and 11 months for those with recurrence after 29.5 months. The median total tumor volume was 29.224 mL (~30 mL). One grade 4 toxicity was observed. Conclusion: Radiosurgery can be used effectively as salvage therapy in ultra-large inoperable gliomas.
E. Yilmaz, E. Ozgur, S.b.gazioglu Gazioglu, C.k. Akbas, U. Gezer, Ph.d., E.e. Yoruker,
Volume 22, Issue 1 (1-2024)
Abstract
Background: Pericentric human satellite II (HSATII) and III (HSATIII) have been shown to be associated with stress response. Expression status of these satellite repeats has not yet been investigated under radiation-induced genotoxic stress. We evaluated the HSATII and HSATIII expression changes under genotoxic stress in cancer cells. Materials and Methods: Cell line MCF-7 and cell line HCT-15 were irradiated with 2 and 5 Gy of ionizing radiation, and cell death rates, as a consequence of genotoxic stress, were determined by flow cytometry. The expression of HSATII and HSATIII expressions was assessed by RT-qPCR. Results: Radiation exposure induced a considerable level of cell death in a dose-dependent manner in both cell types. Compared to untreated cells, HSATII expression declined in MCF-7 cells which were exposed to 2 and 5 Gy radiation, respectively. In HCT-15 cells, the effect of radiation on the HSATII expression was not unified; only higher radiation dose led to a decrease of HSATII expression while 2 Gy increased HSATII expression. The effect of radiation on the HSATIII repeat expression was more pronounced in HCT-15 cells: in MCF-7 cells, HSATIII expression was decreased by 2- and 5-Gy, respectively (p=0.01). In the HCT-15 cells, the rates of HSATIII down-regulation were 3-fold and 2.8 fold by 2- and 5 Gy (p=0.0002 and p=0.02, respectively). Conclusion: Our findings reveal that genotoxic stress induced by ionizing radiation is associated with a decrease in the expression of pericentric satellites and the expression status of HSATII in these conditions may be dose- and/or cellular context-specific.
M.d., S. Barlaz Us, E.b. Yilmaz, Y. Balci, M.b. Çelik,
Volume 23, Issue 2 (5-2025)
Abstract
Background: In this study, it was aimed to evaluate the radiation doses to the heart and uncommon critical organs such as left anterior descending (LAD) and brachial plexus (BP), in breast cancer patients irradiated with tomotherapy. Methods and Materials: Eighty patients with primary breast cancer received whole breast and supraclavicular region radiotherapy (RT) with helical tomotherapy were evaluated. The patients were divided into 4 groups according to the surgical procedure performed right mastectomy (RM-Group 1), left mastectomy (LM-Group 2), right breast-conserving surgery (R-BCS) (Group 3), and left breast-conserving surgery (L-BCS-Group 4). The homogeneity index (HI) for target volume, total volume (V), maximum doses (Dmax), and mean doses (Dmean) for LAD and ipsilateral BP and V, Dmean, V5 (volume of received 5 Gy) and V25 (volume of received 25 Gy) were determined for the heart to all groups. Results: According to the results, HI’s were almost the same in all groups (~1.08). Although the dosimetric parameters for the heart were higher in the left breast irradiations there was a statistical difference between the groups. Dosimetric parameters of LAD are also similar to cardiac dose. However, the increase in the left breast is more pronounced. The brachial plexus dose parameters of all groups were close to each other. Conclusion: It is recommended that the brachial plexus dose should be included in routine dosimetric evaluation in terms of minimizing the risk of radiation-induced plexopathy. Also, the LAD dose should be evaluated with the heart dose to reduce the cardiotoxic effects that may occur after radiotherapy.
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