Would you offer adjuvant pelvic RTto a patient with distal sigmoid colon adenocarcinoma, following LAR with pT4a pN1 with + radial margins and no room for further resection?

If there was no further resection and the initial LAR showed a pT4a (visceral peritoneum), pN1 pelvic nodal disease with positive radial margins, would you give a dose higher than 50.4 Gy in 28 fractions? What factors would lead you to treat a sigmoid colon cancer with adjuvant radiation therapy?