External radiation in stage I (Royal Marsden system) seminoma is given to para-aortic lymphnodes with total doses between 26 and 30 Gy. In stage IIa/IIb additional treatment of ipsilateral iliac nodes up to 30 Gy (stage IIa) and 36 Gy (stage IIb) is recommended. In patients with bulky abdominal disease (stage IIc) whole abdominal irradiation with doses between 25 and 30 Gy followed by a small field to encompass residual masses (15-20 Gy) can be offered as primary treatment. Prophylactic supradiaphragmatic irradiation is not advocated.