How would you manage adjuvant therapy in a gross totally resected favorable site embryonal RMS with resected positive lymph nodes?

For a stage I, favorable site, group IIb (LN+) embryonal RMS where both the primary and LN have been gross totally resected (margins negative), can radiation volume be limited to the involved lymph node chain, thus excluding the primary postop bed? i.e. for para-testicular or non-parameningeal H&N primary sites