Randomized, Multicenter, Phase III Trial to Assess Conformal Post-operative Radiotherapy vs. Surveillance After Complete Resection of Stage II/III Thymoma (RADIO-RYTHMIC-01)

Inclusion criteria

• ✓. 18 \< Age \< 75 years old
• ✓. ECOG performance status ≤1
• ✓. Preoperative chemotherapy is allowed. Maximum of 4 cycles are authorized. Surgery should be realized ≤ 2 months after the last chemotherapy injection.
• ✓. Histologically diagnosed thymoma at pathological examination of surgical specimen after pathological review; for note, centralized, real-time, systematic pathological review is standard through the RYTHMIC network in France
• ✓. Complete resection at pathological examination of the surgical specimen after surgery conducted through standard, recommended approach ensuring accurate assessment of resection status
• ✓. Stage IIb or III disease according to the Masaoka-Koga staging system; this corresponds to stage pT1a with capsule invasion, until stage pT3 N0 M0 in the 8th TNM staging system TNM UICC/AJCC
• ✓. Availability of thoracic Computed-Tomography (CT) scan with IV contrast (in the absence of contra-indications) or PET scan performed before surgery
• ✓. Availability of a thoracic Computed-Tomography (CT) scan with IV contrast (in the absence of contra-indications) showing absence of residual disease after surgical resection of the tumor