Study on Proton Radiotherapy of Thymic Malignancies

All doses are recorded in Gy(RBE). After having checked all eligibility criteria patients will receive: * Patients with radical surgery and unfavourable histology (B2, B3, C) and/or Masaoka-Koga stage III, IVa: 2 Gy(RBE), once daily, five days a week to a total dose of 50 Gy(RBE). * Patients with non-radical surgery (R1 resection) regardless of stage and histology: 2.3 Gy(RBE), once daily, 5 days a week to a total dose of 57.5 Gy(RBE) * Inoperable patients regardless of stage and histology and patients with R2 non-radical resection: 2.5 Gy (RBE), once daily, 5 days a week to a total dose of 62.5 Gy(RBE) * Patients not willing to participate in study will receive photon therapy according to local practice (≥45 Gy) Induction or adjuvant chemotherapy may be used according to local practice. Concomitant chemotherapy is not allowed.