Browsing by Author "Onal, Cem"

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Changes in radiotherapy practice during COVID-19 outbreak in Turkey: A report from the Turkish Society for Radiation Oncology
(ELSEVIER IRELAND LTD, 2020-01-01) Anacak, Yavuz; Onal, Cem; Ozyigit, Gokhan; Agaoglu, Fulya; Akboru, Halil; Akyurek, Serap; Gursel, Bilge; Igdem, Sefik; Yalman, Deniz; Yildiz, Ferah; Saglam, Esra Kaytan
National Multi-Center Observational Retrospective Study to Understand Treatment Patterns and Outcomes for Stage III Non-Small Cell Lung Cancer Patients in Turkey: Turkish Society for Radiation Oncology Study, STONE Trial
(AKAD DOKTORLAR YAYINEVI, 2022-01-01) Onal, Cem; Demiral, Ayse Nur; Atalar, Banu; Yalman, Deniz; Dagoglu, Nergiz; Hurmuz, Pervin; Erpolat, Petek; Akyurek, Serap; Gul, Sute Karabulut; Berber, Tanju; Guler, Ozan Cem; Umay, Cenk; Sert, Fatma; Karahacioglu, Eray; Birgi, Sumerya Duru; Yaprak, Gokhan; Saglam, Esra Kaytan
This study investigated treatment patterns and outcomes in patients with inoperable stage III non-small cell lung cancer (NSCLC) treated with radiotherapy (RT) in Turkey. We included 492 patients with stage III NSCLC in this multi-center retrospective study. Pa-tient demographics, clinical characteristics, and clinical treatment patterns from the time of the initial diagnosis to disease progression were recorded. Additionally, the prognostic factors predicting overall survival (OS) and progression-free survival (PFS) were analyzed. For the initial treatment, 429 patients (89.2\%) received chemotherapy and RT, whereas 53 patients (10.8\%) were treated only with RT. The first disease progression occurred in 288 patients (58.4\%) at 9.3 months (median) after the initial treatment, and 64.6\% re-ceived treatment after first progression. The second disease progression occurred in 30 patients, and 20 patients (66.7\%) received treatment. Median OS and PFS were 27.0 months and 13.4 months, respectively. Age (p< 0.001), stage (p= 0.04), poor performance score (PS) (p= 0.03) and RT doses (p= 0.002) were independent predictors for OS and PFS in our multivariate analysis. Additional significant predictors for OS in the multivariate analysis were gender (p= 0.004), treatment period (0.02), and irradiation technique (p= 0.02). Disease progression occurred in nearly 58\% of the patients, and one-third of these patients remained untreated during the disease progression. These findings indicate a need for additional treatment options in patients with unresectable stage III NSCLC with high-risk features, namely older age, stage IIIB disease, poor PS, and lower RT doses.
Primary extranodal lymphoma of the glands. Literature review and options for best practice in 2019
(ELSEVIER SCIENCE INC, 2019-01-01) Belkacemi, Yazid; Sio, Terence T.; Colson-Durand, Laurianne; Onal, Cem; Villa, Salvador; Anacak, Yavuz; Krengli, Marco; Thariat, Juliette; Ugurluer, Gamze; Miller, Robert C.; Mirimanoff, Rene-Olivier; Ozsahin, Mahmut; To, Nhu Hanh
Primary extranodal non-Hodgkin's lymphomas (EN-NHL) are a heterogeneous group of malignancies that involve numerous entities with significant difference in terms of tumor site locations, prognostic factors, biology expression, and therapeutic options. In the literature, many EN-NHL types were reported from limited series which only allowed narrow views for elucidating prognostic factors and defining the role of loco-regional therapies in the era of new systemic and biologically targeted therapies. The Rare Cancer Network (RCN), an international multidisciplinary consortium, has published a number of reports on several EN-NHL sites which included many gland locations. In this review, we will focus on the recent literature for a selected number of EN-NHL types in both exocrine and endocrine gland locations. We aim to provide renewed and clear messages for the best practice in 2019 for diagnosis, histopathology, treatments, and also their prognostic implications. We believe that better understanding of molecular and genetic characteristics of these particular diseases is crucial for an appropriate management in the era of personalized treatment developments.
The potential role of MR-guided adaptive radiotherapy in pediatric oncology: Results from a SIOPE-COG survey
(ELSEVIER IRELAND LTD, 2021-01-01) Seravalli, Enrica; Kroon, Petra S.; Buatti, John M.; Hall, Matthew D.; Mandeville, Henry C.; Marcus, Karen J.; Onal, Cem; Ozyar, Enis; Paulino, Arnold C.; Paulsen, Frank; Saunders, Daniel; Tsang, Derek S.; Wolden, Suzanne L.; Janssens, Geert O.
Background and purpose: Magnetic resonance guided radiotherapy (MRgRT) has been successfully implemented for several routine clinical applications in adult patients. The purpose of this study is to map the potential benefit of MRgRT on toxicity reduction and outcome in pediatric patients treated with curative intent for primary and metastatic sites. Materials and methods: Between May and August 2020, a survey was distributed among SIOPE- and COG-affiliated radiotherapy departments, treating at least 25 pediatrics patients annually and being (candidate) users of a MRgRT system. The survey consisted of a table with 45 rows (clinical scenarios for primary (n = 28) and metastatic (n = 17) tumors) and 7 columns (toxicity reduction, outcome improvement, PTV margin reduction, target volume daily adaptation, online re-planning, intrafraction motion compensation and on-board functional imaging) and the option to answer by `yes/no'. Afterwards, the Dutch national radiotherapy cohort was used to estimate the percentage of pediatric treatments that may benefit from MRgRT. Results: The survey was completed by 12/17 (71\% response rate) institutions meeting the survey inclusion criteria. Responders indicated an `expected benefit' from MRgRT for toxicity/outcome in 7\% (for thoracic lymphomas and abdominal rhabdomyosarcomas)/0\% and 18\% (for mediastinal lymph nodes, lymph nodes located in the liver/splenic hilum, and liver metastases)/0\% of the considered scenarios for the primary and metastatic tumor sites, respectively, and a `possible benefit' was estimated in 64\%/46\% and 47\%/59\% of the scenarios. When translating the survey outcome into a clinical perspective a toxicity/outcome benefit, either expected or possible, was anticipated for 55\%/24\% of primary sites and 62\%/38\% of the metastatic sites. Conclusion: Although the benefit of MRgRT in pediatric radiation oncology is estimated to be modest, the potential role for reducing toxicity and improving clinical outcomes warrants further investigation. This fits best within the context of prospective studies or registration trials.
The present and future opportunities of the Rare Cancer Network: an international consortium for advancement of oncologic care
(SAGE PUBLICATIONS LTD, 2015-01-01) Sio, Terence T.; Mirimanoff, Rene-Olivier; Ozyar, Enis; Belkacemi, Yazid; Miller, Robert C.; Villa, Salvador; Thariat, Juliette; Krengli, Marco; Scandolaro, Luciano; Atalar, Banu; Ugurluer, Gamze; Gutierrez Garcia, Beatriz; Ashman, Jonathan B.; Anacak, Yavuz; Onal, Cem; Arat, Mutlu; Sun, Xu Shan; Tesanovic, Dusanka; Lassen-Ramshad, Yasmin; Oksuz, Didem; Dincbas, Fazilet; Sezen, Duygu; Akyurek, Serap; Kutuk, Tugce; Bolukbasi, Yasemin; Eren, Gulnihan; Paryani, Nitesh N.; Ahmed, Safia K.; Moretti, Luigi; Merrell, Kenneth W.; Chang, Kenneth; Mayeda, Mark; Arnett, Andrea L.; Habboush, Jacob Y.; Ozsahin, Mahmut; Network, Rare Canc
To date, the Rare Cancer Network (RCN) has initiated more than 90 studies and 54 peer-reviewed publications were produced as a result. The Second International Symposium of the Rare Cancer Network recently took place in Istanbul, Turkey on April 17-18, 2015, and update was given on multiple currently ongoing projects, while also giving room for new proposals which will shape the direction of future studies for the group. This companion issue of the RCN Proceedings summarized the findings of this meeting, while also serving as a call for fresh projects and papers which will continue to energize the group and advance the oncologic science. A brief introduction to the principles, history, and vision of the RCN was also included. To review, the academic year of 2014-15 marked an enormous success for the international members of the RCN, with the generation of 8 fully published papers and more than 12 newly proposed topics. By the collective efforts of all RCN members, in the future, we look forward to the upcoming opportunities in continuing to advance the standard of chemo-and radiotherapeutic oncologic care for selected rare tumor topics. The studies of these rare cancers often do not allow the design and execution of prospectively enrolled trials