Abstract 1742TiP
Background
Thymomas are rare intrathoracic malignancies that may be aggressive and difficult to treat. Knowledge and level of evidence for treatment strategies are mainly based on restrospective studies or expert opinions. The mainstay of treatment is surgery. However, after curative thymectomy associated with thymomectomy, there is a total of 30% of relapses. Currently there is no strong evidence that post-operative radiotherapy (PORT) after complete resection of localized thymoma is associated with survival benefit in patients. RADIORYTHMIC is a phase III, randomized trial aiming at comparing PORT versus surveillance after complete resection of Masaoka-Koga stage IIb/III thymoma.
Trial design
314 patients will be included; randomisation 1:1 will attribute either PORT (52Gy to the mediastinum using Intensity-Modulated Radiation Therapy or Proton-Beam Therapy) according to established national guidelines, or surveillance. Stratification criteria include histologic grading (thymoma type A, AB, B1 considered as low grade versus B2, B3 considered as high grade tumors), stage, and delivery of preoperative chemotherapy. Patients’ recruitment will be made through the French RYTHMIC network of 15 expert centers participating to a nationwide multi-disciplinary tumor board. Follow-up will last 7 years. Primary endpoint is Recurrence-Free Survival. Secondary objectives include overall survival, the assessment of acute and late toxicities with a particular attention to cardiac toxicities, and analysis of prognoTrial stic and predictive biomarkers. Expected results: The first patients were included in March 2021, and the inclusion period will last 4 years, with results expected in 2028. The originality of this work is due to: 1)The use of national established guidelines for PORT since there is no clear international recommendations for mediastinal irradiation; 2)The quality insurance of PORT with a systematic national review of first cases in each radiation center; 3)This is the first randomized prospective large trial evaluating PORT in thymoma.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Hospital Institut Curie Paris.
Funding
INCa.
Disclosure
All authors have declared no conflicts of interest.