Stage I seminoma represents approximately 40% of all germ-cell testicular cancers. For more than 50 years, adjuvant radiation therapy (RT) has been the standard of care for patients with such seminomas following radical orchiectomy. Relapses occur in fewer than 5% of patients treated with adjuvant RT, and almost all patients who relapse can be cured with cisplatin-based salvage chemotherapy.[1] In recent years, the majority of research on stage I seminoma has focused on minimizing the toxicity from...