TR-Dizin Açık Erişimli Yayınlar

Permanent URI for this collectionhttps://hdl.handle.net/11727/10759

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2014 - 20195

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Author: search.filters.author.Onal, CemHas files: Yes

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    The Comparision of Breast Cancer in the Young and Elderly Patients
    (2019) Petek Erpolat, Ozge; Yuce Sari, Sezin; Ergen, Sefika Arzu; Aydin, Barbaros; Akkus, Berna; Gultekin, Melis; Copan Oksuz, Didem; Arican, Zumre; Onal, Cem; Gursel, Bilge; Akmansu, Muge; Ozyigit, Gokhan; Bilkay Gorken, Ilknur; Yildiz, Ferah
    OBJECTIVE To compare the tumor characteristics, treatment approaches, recurrence patterns and survival results rates of young and elderly patients with breast cancer. METHODS In this study, Between between 2000-2013, a total of 779 patients were treated for breast cancer at nine radiation oncology departments were evaluated retrospectively. Three-hundred eight four of these patients were young (<= 35 years), and 395 of those the patients were elderly (>= 70 years). RESULTS Young patients were more likely to present with aggressive tumor features. They were more often received comprehensive lymphatic irradiation, tumor bed boost and intense chemotherapy. No difference was found for 5 and 10-year loco-regional recurrence- free survival rates were (96% and 93% for young, 97% and 97% for elderly). The 5 and 10-year distant recurrence- free survival rates were lower in the young patients (77% and 67% for young, 85% and 85% for elderly, p<0.0001). No difference was found in 5 and 10-year breast cancer- specific survival (91% and 79% for young, 92% and 87% for elderly). The 5 and 10-year overall survival rates were higher in the young patients (92% and 78% for young, 78% and 63% for elderly, p<0.0001). CONCLUSION The reason for the similarity between the age groups in terms ofregarding loco-regional recurrence- free survival can be more comprehensive lymphatic irradiation and tumor bed boost, the young patients received. The distant recurrence- free survival rates rates were significantly lower in the young patients even though they received more intensive chemotherapy. Future studies aimed at more effective systemic regimens to decrease distant recurrence in young patients are warranted.
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    Effects of Setup Errors on Dose Distribution for Tangential Wedge Field and Field-in-Field Techniques During Breast Irradiation
    (2014) Sonmez, Aydan; Onal, Cem; Sonmez, Serhat; Arslan, Gungor; Parlak, Cem; Topkan, Erkan; Yavuz, Melek
    This study is aimed to evaluate the effects of setup errors on dose distribution for target volume and healthy tissue within the irradiated volume and also critical surrounding organs for breast radiotherapy (RT) using both the tangential field and the field-in-field (FIF) technique. Ten patients with breast cancer were enrolled. For each patients two plans were generated; tangential field plan and FIF-plan. The setup errors were simulated for a series of displacements of +/- 5 mm and +/- 10 mm in superior-inferior (x-axis), medial-lateral (y-axis), and anterior-posterior (z-axis) directions and dose volume comparisons were made both between and within groups. The most prominent changes were observed in setup errors at z-axis. In wedge plan, 10-mm setup error at the +z axis caused a significant decrease in tumor coverage compared with the plan with no setup error (96.5% vs. 99.2%; p= 0.01). The 5 and 10 mm setup errors at the +z-axis resulted in significantly higher healthy tissue doses in wedge plans compared with FIF plans. The setup errors along z-axis had a significant effect on the dose distribution for target volume and also to the lungs. The setup error in the isocenter should be kept strictly below 5 mm.
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    Three Dimensional Conformal Radiotherapy and Androgen Deprivation Therapy in Patients with Clinically Localized Prostate Cancer; Hacettepe University Experience
    (2015) Ozdemir, Yurday; Akyol, Fadil; Ozyiğit, Gokhan; Hurmuz, Pervin; Onal, Cem; Selek, Ugur; Karabulut, Erdem
    The aim of this study into evaluate the treatment results of three dimensional conformal radiotherapy (3DCRT) and androgen deprivation therapy (ADT) in patients with clinically localized prostate cancer (CLPC). Between June 1998 and December 2011, 577 patients with the diagnosis of CLPC were treated. ADT was started 3 months prior to radiotherapy (RT). 3DCRT was delivered to prostate and the seminal vesicles (SV) to a total dose of 70Gy. Additionally, patients with lymph node (LN) positivity received 50.4Gy RT to pelvic LN's. Median follow up time was 65 months. Five-ten years overall survival (OS), cause specific survival (CSS), PSA relapse-free survival (PSA-RFS) and distant metastasis-free survival (DMFS) rates were 92-74%, 97-91%, 77-55% and 94-88%, respectively. OS was negatively affected from LN positivity (p < 0.001). In the subgroup of patients With GS 8, there was no significant difference between < 1 years and 1 years of ADT in terms of CSS, PSA-RFS and DMFS. OS was better in patients with < 1 years of ADT (p = 0.01). Five year OS (p = 0.02), CSS (p = 0.05), PSA-RFS (p = 0.01) and DMFS (p = 0.07) rates were inferior in the high risk group patients that used ADT 1 year. Acute and late RTOG grade III/IV gastrointestinal system toxicity rates were 1.7% and 5% and acute and chronic RTOG grade III/IV genitourinary system toxicity rates were 1.4% and 5%, respectively. 3DCRT and ADT combination is an effective treatment modality with acceptable toxicities in patients with clinically localized prostate cancer.
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    Review of Current Status of Radiotherapy Facilities and Assessment of Required Time for Radiotherapy Delivery Workflow in Turkey: On Behalf of Turkish Society for Radiation Oncology
    (2015) Akman, Fadime; Onal, Cem; Kamer, Serra; Agaoglu, Fulya; Guney, Yildiz; Hicsonmez, Ayse; Koc, Mehmet; Oksuz, Didem C.; Ozyiğit, Gokhan; Ozkok, Serdar
    The aim this study is to evaluate current status and workload of radiotherapy (RT) centers in Turkey, by assessing time and staff required during core treatment procedures in patients with different tumor sites. A survey sent via e-mail to all hospitals that are actively treating patients with RT, that aimed expose the details on type of the techniques being used and the time spent for treatment planning and delivery for the different techniques according to different tumor sites. The results were evaluated by several variables, the type of the center (university hospitals or state-run hospitals) and the number of patients treated per year per center (<1000 patients/year treated vs. 000 patients/year treated). The survey was sent to 48 centers and the return rate was 71% (34 centers). Average daily treatment course performed by one physician was 192 per year (range: 41 - 650). Median number of patients treated by a specialist per year was 210 (range: 79 - 650) in the university hospitals and 101 (range: 41 - 167) in the state-run hospitals. Median time spent for treating a patient with 3-dimensional conformal RT (3DCRT) was 4 h, and it was 5 h 45 min for intensity-modulated AT (IMRT). The time spent for all cancer types treated with 3DCRT and IMRT was higher in state-run hospitals compared to university hospitals. With increasing use of newer AT techniques, the time spent for treating patients increases. Besides adequate equipment, sufficient and well-trained staff is required to achieve these newer AT technique benefits for the patients.
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    Prognostic Value of Metabolic Response Measured by FDG-PET-CT in Patients with Breast Cancer Liver Metastasis Treated with Stereotactic Body Radiotherapy
    (2018) Guler, Ozan Cem; Torrun, Nese; Akkus Yildirim, Berna; Onal, Cem; 0000-0001-6908-3412; AAC-5654-2020
    OBJECTIVE To investigate the impact of metabolic response measured by 18-fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET-CT) in patients with breast cancer liver metastasis (BCLM) treated with stereotactic body radiotherapy (SBRT). METHODS The medical records of 17 patients with BCLM treated with SBRT between March 2013 and October 2017 were investigated retrospectively. Patients received SBRT for their liver metastasis, and thereafter, a second FDG-PET-CT was performed for response assessment in a median of 4.1 (2.2-8.2) months. A total of 54 Gy in three fractions were delivered to liver metastatic lesions. The standardized uptake value (SUV) and survival rates were evaluated. RESULTS After a median follow-up time of 11.5 (3.2-48.9) months, there was a significant difference between pre- and post-SBRT SUVs (p<0.001). Complete metabolic response was observed in 14 (82%) patients, partial metabolic response was observed in 2 (12%) patients, and stable metabolic disease/progressive metabolic disease was observed in 1 (6%) patient at post-treatment PET-CT. The 1- and 2-year overall survival rates were 68% and 57%, respectively, and the 1- and 2-year progression-free survival rates were 38% and 25%, respectively. CONCLUSION PET-CT is an effective tool for response monitoring in patients with BCLM treated with SBRT.