Inclusion Criteria:  Histological or cytological diagnosis of thymoma or thymic carcinoma. With radical surgery: stage III and IVa and selected stage II with type B2, B3 and thymic carcinoma according to local routine. With non-radical surgery (R1 or R2) or inoperable patient/ patient refusing surgery: stage I - IVa, any histology PS WHO 0 - 2. FEV1 > 1L or >40 % of predicted and CO diffusion capacity > 40% of predicted (postoperative measures) Age >18 years, no upper age limit. Written informed consent from patients.  Exclusion Criteria:  Masaoka-Koga stage IVb (distant metastases). Pregnancy. Serious concomitant systemic disorder incompatible with the study. Tumour motion > 0.5 cm on two repeated 4DCT