How would you treat a pediatric embryonal rhabdomyosarcoma of the kidney with preoperative rupture s/p nephrectomy and getting VAC/VI chemotherapy?

Would you treat this with whole-abdomen RT with a boost? What dose would you recommend? This would be Stage 1, Group 2 (R1 resection), low risk; but likely should be treated more like a Group 3 (R2 resection), intermediate risk given the preoperative rupture. ARST 0531 recommends using 24 Gy in 1.5 Gy/fx if doing whole abdomen RT, and typical dose for R1 resection is 50.4 Gy, but this would be limited by the bowel.