Stage IIA and IIB seminoma includes N1-2 disease, and they are typically treated with either radiation or 3-4 cycles of chemotherapy. The single arm phase 2 SAKK 01/10 trial investigated an approach of combined, but de-escalated, chemotherapy and radiation. Patients (n=116) received a single cycle of carboplatin followed by radiation. While radiation dose was fairly standard (30 Gy in 15 fractions for stage IIA or 36 Gy in 18 fractions for stage IIB), the extent of radiation was de-escalated to include only the involved nodal site. The CTV was a 2 cm craniocaudal and 1 cm axial expansion of the pre-treatment GTV with an additional 1 cm PTV margin. At 3 years, the observed PFS rate was favorable at 93.7%, but it did not meet the target rate of 95%. The rate of grade 3+ toxicity was just 7%.
- Papachristofilou, Lancet Oncol 2022