Araştırma Çıktıları
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Item International Recommendations on Reirradiation by Intensity Modulated Radiation Therapy for Locally Recurrent Nasopharyngeal Carcinoma(ELSEVIER SCIENCE INC, 2021-01-01) Ng, Wai Tong; Soong, Yoke Lim; Ahn, Yong Chan; AlHussain, Hussain; Choi, Horace C. W.; Corry, June; Gregoire, Vincent; Harrington, Kevin J.; Hu, Chao Su; Jensen, Kenneth; Kwong, Dora L.; Langendijk, Johannes A.; Le, Quynh Thu; Lee, Nancy Y.; Lin, Jin Ching; Lu, Tai Xiang; Mendenhall, William M.; O'Sullivan, Brian; Ozyar, Enis; Pan, Jian Ji; Peters, Lester J.; Poh, Sharon S.; Rosenthal, David I.; Sanguineti, Giuseppe; Tao, Yungan; Wee, Joseph T.; Yom, Sue S.; Chua, Melvin L. K.; Lee, Anne W. M.Purpose: Reirradiation for locally recurrent nasopharyngeal carcinoma (NPC) is challenging because prior radiation dose delivered in the first course is often close to the tolerance limit of surrounding normal structures. A delicate balance between achieving local salvage and minimizing treatment toxicities is needed. However, high-level evidence is lacking because available reports are mostly retrospective studies on small series of patients. Pragmatic consensus guidelines, based on an extensive literature search and the pooling of opinions by leading specialists, will provide a useful reference to assist decision-making for these difficult decisions. Methods and Materials: A thorough review of available literature on recurrent NPC was conducted. A set of questions and preliminary draft guideline was circulated to a panel of international specialists with extensive experience in this field for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the whole panel for review and reconsideration. The current guideline was based on majority voting after repeated iteration for final agreement. Results: The initial round of questions showed variations in clinical practice even among the specialists, reflecting the lack of high-quality supporting data and the difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of reirradiation (including patient selection, targets contouring, dose prescription, and constraints). Conclusion: This paper provides useful reference on radical salvage treatment strategies for recurrent NPC and optimization of reirradiation through review of published evidence and consensus building. However, the final decision by the attending clinician must include full consideration of an individual patient's condition, understanding of the delicate balance between risk and benefits, and acceptance of risk of complications. (C) 2021 Elsevier Inc. All rights reserved.Item International Guideline on Dose Prioritization and Acceptance Criteria in Radiation Therapy Planning for Nasopharyngeal Carcinoma(ELSEVIER SCIENCE INC, 2019-01-01) Lee, Anne W.; Ng, Wai Tong; Pan, Jian Ji; Chiang, Chi-Leung; Poh, Sharon S.; Choi, Horace C.; Ahn, Yong Chan; AlHussain, Hussain; Corry, June; Grau, Cai; Gregoire, Vincent; Harrington, Kevin J.; Hu, Chao Su; Kwong, Dora L.; Langendijk, Johannes A.; Le, Quynh Thu; Lee, Nancy Y.; Lin, Jin Ching; Lu, Tai Xiang; Mendenhall, William M.; O'Sullivan, Brian; Ozyar, Enis; Peters, Lester J.; Rosenthal, David I.; Sanguineti, Giuseppe; Soong, Yoke Lim; Tao, Yungan; Yom, Sue S.; Wee, Joseph T.Purpose: The treatment of nasopharyngeal carcinoma requires high radiation doses. The balance of the risks of local recurrence owing to inadequate tumor coverage versus the potential damage to the adjacent organs at risk (OARs) is of critical importance. With advancements in technology, high target conformality is possible. Nonetheless, to achieve the best possible dose distribution, optimal setting of dose targets and dose prioritization for tumor volumes and various OARs is fundamental. Radiation doses should always be guided by the As Low As Reasonably Practicable principle. There are marked variations in practice. This study aimed to develop a guideline to serve as a global practical reference. Methods and Materials: A literature search on dose tolerances and normal-tissue complications after treatment for nasopharyngeal carcinoma was conducted. In addition, published guidelines and protocols on dose prioritization and constraints were reviewed. A text document and preliminary set of variants was circulated to a panel of international experts with publications or extensive experience in the field. An anonymized voting process was conducted to rank the proposed variants. A summary of the initial voting and different opinions expressed by members were then recirculated to the whole panel for review and reconsideration. Based on the comments of the panel, a refined second proposal was recirculated to the same panel. The current guideline was based on majority voting after repeated iteration for final agreement. Results: Variation in opinion among international experts was repeatedly iterated to develop a guideline describing appropriate dose prioritization and constraints. The percentage of final agreement on the recommended parameters and alternative views is shown. The rationale for the recommendations and the limitations of current evidence are discussed. Conclusions: Through this comprehensive review of available evidence and interactive exchange of vast experience by international experts, a guideline was developed to provide a practical reference for setting dose prioritization and acceptance criteria for tumor volumes and OARs. The final decision on the treatment prescription should be based on the individual clinical situation and the patient's acceptance of optimal balance of risk. (C) 2019 Elsevier Inc. All rights reserved.Item International guideline for the delineation of the clinical target volumes (CTV) for nasopharyngeal carcinoma(ELSEVIER IRELAND LTD, 2018-01-01) Lee, Anne W.; Ng, Wai Tong; Pan, Jian Ji; Poh, Sharon S.; Ahn, Yong Chan; AlHussain, Hussain; Corry, June; Grau, Cai; Gregoire, Vincent; Harrington, Kevin J.; Hu, Chao Su; Kwong, Dora L.; Langendijk, Johannes A.; Le, Quynh Thu; Lee, Nancy Y.; Lin, Jin Ching; Lu, Tai Xiang; Mendenhall, William M.; O'Sullivan, Brian; Ozyar, Enis; Peters, Lester J.; Rosenthal, David I.; Soong, Yoke Lim; Tao, Yungan; Yom, Sue S.; Wee, Joseph T.Purpose: Target delineation in nasopharyngeal carcinoma (NPC) often proves challenging because of the notoriously narrow therapeutic margin. High doses are needed to achieve optimal levels of tumour control, and dosimetric inadequacy remains one of the most important independent factors affecting treatment outcome. Method: A review of the available literature addressing the natural behaviour of NPC and correlation between clinical and pathological aspects of the disease was conducted. Existing international guidelines as well as published protocols specified by clinical trials on contouring of clinical target volumes (CTV) were compared. This information was then summarized into a preliminary draft guideline which was then circulated to international experts in the field for exchange of opinions and subsequent voting on areas with the greatest controversies. Results: Common areas of uncertainty and variation in practices among experts experienced in radiation therapy for NPC were elucidated. Iterative revisions were made based on extensive discussion and final voting on controversial areas by the expert panel, to formulate the recommendations on contouring of CTV based on optimal geometric expansion and anatomical editing for those structures with substantial risk of microscopic infiltration. Conclusion: Through this comprehensive review of available evidence and best practices at major institutions, as well as interactive exchange of vast experience by international experts, this set of consensus guidelines has been developed to provide a practical reference for appropriate contouring to ensure optimal target coverage. However, the final decision on the treatment volumes should be based on full consideration of individual patients' factors and facilities of an individual centre (including the quality of imaging methods and the precision of treatment delivery). (C) 2017 Elsevier B.V. All rights reserved.Item 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 CancTo 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 trialsItem Clinical adoption patterns of 0.35 Tesla MR-guided radiation therapy in Europe and Asia(BMC, 2022-01-01) Slotman, Berend J.; Clark, Mary Ann; Ozyar, Enis; Kim, Myungsoo; Itami, Jun; Tallet, Agnes; Debus, Juergen; Pfeffer, Raphael; Gentile, PierCarlo; Hama, Yukihiro; Andratschke, Nicolaus; Riou, Olivier; Camilleri, Philip; Belka, Claus; Quivrin, Magali; Kim, BoKyong; Pedersen, Anders; Felter, Mette van Overeem; Kim, Young Il; Kim, Jin Ho; Fuss, Martin; Valentini, VincenzoBackground Magnetic resonance-guided radiotherapy (MRgRT) utilization is rapidly expanding, driven by advanced capabilities including better soft tissue imaging, continuous intrafraction target visualization, automatic triggered beam delivery, and the availability of on-table adaptive replanning. Our objective was to describe patterns of 0.35 Tesla (T)-MRgRT utilization in Europe and Asia among early adopters of this novel technology. Methods Anonymized administrative data from all 0.35T-MRgRT treatment systems in Europe and Asia were extracted for patients who completed treatment from 2015 to 2020. Detailed treatment information was analyzed for all MR-linear accelerators (linac) and -cobalt systems. Results From 2015 through the end of 2020, there were 5796 completed treatment courses delivered in 46,389 individual fractions. 23.5\% of fractions were adapted. Ultra-hypofractionated (UHfx) dose schedules (1-5 fractions) were delivered for 63.5\% of courses, with 57.8\% of UHfx fractions adapted on-table. The most commonly treated tumor types were prostate (23.5\%), liver (14.5\%), lung (12.3\%), pancreas (11.2\%), and breast (8.0\%), with increasing compound annual growth rates (CAGRs) in numbers of courses from 2015 through 2020 (pancreas: 157.1\%Item 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.Item History of the Rare Cancer Network and past research(PAGEPRESS PUBL, 2014-01-01) Mirimanoff, Rene-Olivier; Ozsahin, Mahmut; Thariat, Juliette; Ozyar, Enis; Schick, Ulrike; Pehlivan, Berrin; Krengli, Marco; Pellanda, Alessandra Franzetti; Vees, Hansjoerg; Cai, Ling; Scandolaro, Luciano; Belkacemi, Yazid; Villa, Salvador; Igdem, Sefik; Lutsyk, Myroslav; Miller, Robert C.Approximately, twenty years ago, the Rare Cancer Network (RCN) was formed in Lausanne, Switzerland, to support the study of rare malignancies. The RCN has grown over the years and now includes 130 investigators from twenty-four nations on six continents. The network held its first international symposium in Nice, France, on March 21-22, 2014. The proceedings of that meeting are presented and contains the abstracts of fourteen oral presentations made at the meeting of prior RCN studies. From 1993 to 2014, 74 RCN studies have been initiated, of which 54 were completed, 10 are in progress or under analysis, and 9 were stopped due to poor accrual. Forty-four peer reviewed publications have been written on behalf of the RCN.Item Management of symptomatic radiation necrosis after stereotactic radiosurgery and clinical factors for treatment response(KOREAN SOC THERAPEUTIC RADIOLOGY \& ONCOLOGY, 2020-01-01) Sayan, Mutlay; Mustafayev, Teuta Zoto; Balmuk, Aykut; Mamidanna, Swati; Kefelioglu, Erva Seyma Sare; Gungor, Gorkem; Chundury, Anupama; Ohri, Nisha; Karaarslan, Ercan; Ozyar, Enis; Atalar, BanuPurpose: Approximately 10\% of patients who received brain stereotactic radiosurgery (SRS) develop symptomatic radiation necrosis (RN). We sought to determine the effectiveness of treatment options for symptomatic RN, based on patient-reported outcomes. Materials and Methods: We conducted a retrospective review of 217 patients with 414 brain metastases treated with SRS from 2009 to 2018 at our institution. Symptomatic RN was determined by appearance on serial magnetic resonance images (MRIs), MR spectroscopy, requirement of therapy, and development of new neurological complaints without evidence of disease progression. Therapeutic interventions for symptomatic RN included corticosteroids, bevacizumab and/or surgical resection. Patient-reported therapeutic outcomes were graded as complete response (CR), partial response (PR), and no response. Results: Twenty-six patients experienced symptomatic RN after treatment of 50 separate lesions. The mean prescription dose was 22 Gy (range, 15 to 30 Gy) in 1 to 5 fractions (median, 1 fraction). Of the 12 patients managed with corticosteroids, 6 patients (50\%) reported CR and 4 patients (33\%) PR. Of the 6 patients managed with bevacizumab, 3 patients (50\%) reported CR and 1 patient (18\%) PR. Of the 8 patients treated with surgical resection, all reported CR (100\%). Other than surgical resection, age >= 54 years (median, 54 yearsItem Long-term toxicity and survival outcomes after stereotactic ablative radiotherapy for patients with centrally located thoracic tumors(WALTER DE GRUYTER GMBH, 2020-01-01) Atalar, Banu; Mustafayev, Teuta Zoto; Sio, Terence T.; Sahin, Bilgehan; Gungor, Gorkem; Aydin, Gokhan; Yapici, Bulent; Ozyar, EnisBackground. Stereotactic ablative radiotherapy (SABR) is effective for thoracic cancer and metastasesItem Intensity modulated radiotherapy (IMRT) in bilateral retinoblastoma(ASSOC RADIOLOGY \& ONCOLOGY, 2010-01-01) Atalar, Banu; Ozyar, Enis; Gunduz, Kaan; Gungor, GorkemBackground. External beam radiotherapy (EBRT) for retinoblastoma has traditionally been done with conventional radiotherapy techniques which resulted high doses to the surrounding normal tissues. Case report. A 20 month-old girl with group D bilateral retinoblastoma underwent intensity modulated radiotherapy (IMRT) to both eyes after failing chemoreduction and focal therapies including cryotherapy and transpupillary thermotherapy. In this report, we discuss the use of IMRT as a method for reducing doses to adjacent normal tissues while delivering therapeutic doses to the tumour tissues compared with 3-dimensional conformal radiotherapy (3DCRT). At one year follow-up, the patient remained free of any obvious radiation complications. Conclusions. Image guided IMRT provides better dose distribution than 3DCRT in retinoblastoma eyes, delivering the therapeutic dose to the tumours and minimizing adjacent tissue damage.
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