Study Protocol
AB052. Indications for postoperative radiation therapy for thymic tumors based on the new ninth TNM stage classification: a protocol of a multicenter, retrospective study
Gerrit Fabian Flier1, Sonja Adebahr1, Tanja Schimek-Jasch1, Anca Ligia Grosu1, Bernward Passlick2, Wolfgang Jungraithmayr3, Andreas Rimner1
1Department of Radiation Oncology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, German Cancer Consortium (DKTK), partner site DKTK-Freiburg, Freiburg, Germany;
2Department of Thoracic Surgery, University Hospital Freiburg, Freiburg, Germany;
3Department of Thoracic Surgery, University Hospital Rostock, Rostock, Germany
Correspondence to: Andreas Rimner, MD. Department of Radiation Oncology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, German Cancer Consortium (DKTK), partner site DKTK-Freiburg, Robert-Koch-Straße 3, Freiburg im Breisgau, 79106, Germany. Email: andreas.rimner@uniklinik-freiburg.de.
Background: The indication for radiation therapy in thymic tumors requires more precise definition, particularly in light of the recently established 9th edition tumor-node-metastasis (TNM) classification. While surgical treatment is already aligned with the TNM system, radiation oncologists still primarily rely on the Masaoka-Koga classification due to the absence of TNM-based data on postoperative radiation therapy (PORT). Here we present our study protocol and project plan for an international, multi-center, retrospective study to evaluate the outcomes after surgical resection and PORT in thymic tumors using both the Masaoka-Koga and TNM classifications. We aim to define the role of PORT in the context of the new TNM staging system.
Methods: This study focuses on patients with completely resected (R0) Masaoka-Koga stages I–III thymomas, thymic carcinomas, and neuroendocrine thymic tumors (NETTs), with and without PORT. Recruitment of international partner institutions is ongoing to establish a large and diverse patient cohort. In addition to tumor stage, the study collects variables related to surgical outcomes, radiation therapy doses, target volumes, and oncologic
Discussion: Preliminary data from the Freiburg University Hospital identified 52 patients for the study. The observation period for our study spans from January 1, 2010, to June 1, 2024. The cohort included 45 thymomas, 2 NETTs, and 5 thymic carcinomas. The median follow-up period was 46.1 months. According to the TNM classification, 49 patients were classified as stage I, 2 as stage II, and 1 as stage III. The median age was 60.5 years; 23 patients were male and 29 were female. Paraneoplastic syndromes were observed in 18 of the 52 patients, including 17 cases of myasthenia. 10 patients received PORT, with a median dose of 50 Gy. We have received verbal commitments from 55 centers worldwide to participate in this project. The geographic distribution of these centers includes 32 from Europe, 13 from North America, and 10 from Asia. Contracting for data exchange with these centers is ongoing, and we are actively seeking additional institutions to support the development of a new indication for PORT in thymic tumors. We expect to collect the data until the end of 2025.
Trial Registration: None.
Keywords: Postoperative radiation therapy (PORT); Masaoka-Koga classification; 9th TNM stage classification
Acknowledgments
None.
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://med.amegroups.com/article/view/10.21037/med-25-ab052/coif). A.R. reports grants or contrasts from AstraZeneca, Merck, Boehringer Ingelheim, Pfizer and Varian Medical Systems, consulting fees from AstraZeneca, Merck and MoreHealth, payments or honoraria from Boehringer Ingelheim, and support for attending meeting or travel from AstraZeneca. A.R. also reports participation in Merck, IMIG, ABR and ITMIG. S.A. reports support from the Federal Ministry of Education and Research (BMBF). The other authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
doi: 10.21037/med-25-ab052
Cite this abstract as: Flier GF, Adebahr S, Schimek-Jasch T, Grosu AL, Passlick B, Jungraithmayr W, Rimner A. AB052. Indications for postoperative radiation therapy for thymic tumors based on the new ninth TNM stage classification: a protocol of a multicenter, retrospective study. Mediastinum 2025;9:AB052.
