Appropriate radiation volume for stage IIA/B testicular seminoma

Prophylactic left supraclavicular fossa irradiation has been suggested to reduce relapse rates in patients treated for Stage IIA/B testicular seminoma. To address this issue, we reviewed patterns of failure and treatment outcome in patients treated with radiation therapy at our institution.Between 1981 and 1999, 79 men with Stage II seminoma (IIA, 49; IIB, 30) were treated with radiation therapy (RT) to the para-aortic and ipsilateral (+/- contralateral) pelvic lymph nodes (dose: 25-35 Gy).With a median follow-up of 8.5 years, the 5-year relapse-free rate was 91% (standard error: 3%), and 2 patients have died of seminoma, giving a 5-year cause-specific survival of 97%. A total of 7 patients have relapsed with 2 isolated to the left supraclavicular fossa. Five of 7 patients have been successfully salvaged.Prophylactic left supraclavicular fossa irradiation might have prevented relapse in 2 of 79 patients in Stage IIA/B seminoma. However, 97% of patients would have received unnecessary left neck RT, so we continue to recommend, as standard treatment, infradiaphragmatic RT only.