TR-Dizin Açık Erişimli Yayınlar
Permanent URI for this collectionhttps://hdl.handle.net/11727/10759
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Item The prognostic value of mean apparent diffusion coefficient measured with diffusion-weighted magnetic resonance image in patients with prostate cancer treated with definitive radiotherapy(2022) Onal, Cem; Erbay, Gurcan; Guler, Ozan Cem; Oymak, Ezgi; 35753556Purpose: To assess the correlation between initial tumor apparent diffusion coefficient (ADC) values and clinicopathological parameters in prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Additionally, the prognostic factors for freedom from biochemical failure (FFBF) and progressionfree survival (PFS) in this patient cohort were analyzed. Materials and methods: The clinical data of 503 patients with biopsy-confirmed PCa were evaluated retrospectively. All patients had clearly evident tumors on diffusion-weighted magnetic resonance imaging (DW-MRI) for ADC values. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PFS. Results: The median follow-up was 72.9 months. The 5-year FFBF and PFS rates were 93.2% and 86.2%, respectively. Significantly lower ADC values were found in patients with a high PSA level; advanced clinical stage; higher ISUP score, and higher risk group than their counterparts. Receiver operating characteristic (ROC) curve analysis revealed an ADC cut-off value of 0.737 x 10-3 mm2/sec for tumor recurrence. Patients who progressed had a lower mean ADC value than those who did not (0.712 +/- 0.158 vs. 1.365 +/- 0. 227 x 10-3 mm2/sec; p < 0.001). There was a significant difference in 5-year FFBF (96.3% vs. 90%; p < 0.001) and PFS rates (83.8% vs. 73.5%; p = 0.002) between patients with higher and lower mean ADC values. The FFBF and PFS were found to be correlated with tumor ADC value and ISUP grades in multivariable analysis. Additionally, older age was found to be a significant predictor of worse PFS. Conclusions: Lower ADC values were found in patients with high-risk characteristics such as a high serum PSA level, stage or grade of tumor, or high-risk disease, implying that ADC values could be used to predict prognosis. Lower ADC values and higher ISUP grades were associated with an increased risk of BF and progression, implying that treatment intensification may be required in these patients. (c) 2022 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 173 (2022) 285-291Item 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, FerahOBJECTIVE 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.Item 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, ErdemThe 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.Item 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-5654-2020OBJECTIVE 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.