Radiation therapy of seminoma: 17-year experience at the Joint Center for Radiation Therapy.

One hundred and sixteen patients with stage I and II primary testicular seminoma were treated at the Joint Center for Radiation Therapy (JCRT) between 1968 and 1984. Complete follow-up is available for 114 patients (98%) with a median follow-up time of 6 years. Actuarial relapse-free survival (RFS) and survival for the entire group at 10 years were 94 and 86%, respectively, with 27 patients still at risk beyond 10 years. Actuarial RFS and survival at 10 years by stage were 97 and 92% for stage I, 93 and 81% for stage IIa, 100 and 100% for stage IIb, but only 75 and 51% for stage IIc. The difference in actuarial survival between stage IIc patients and stage I, IIa and IIb patients was significant (p less than 0.01). These results indicate that radiation therapy is excellent treatment for stage I and II seminomas as long as the largest mass of disease is not greater than 5 cm (stage IIc). Patients with stage IIc seminoma are now treated with cisplatin-containing combination chemotherapy followed by radiation therapy to areas of bulk disease. Although the majority of patients with stage II disease in this series received mediastinal irradiation, this is no longer recommended at the JCRT.