“…Six studies using adjuvant or salvage RT had data on tumor differentiation: 17/268 (6%) tumors were well differentiated, 142/268 (53%) were moderately differentiated, and 109/268 (41%) were poorly differentiated. 9,13,27,30,43,48,50 The main indications for adjuvant RT were PNI in 11 studies 6,9,20,27,28,30,42,[46][47][48]56 and positive margins or recurrent tumors in 8 studies 13,19,30,41,44,49,50,55 (See Supplemental Digital Content 2, Table 5, http://links.lww.com/ DSS/A713). Most studies did not differentiate between adjuvant and salvage RT nor delineate outcomes based on treatment type (i.e., adjuvant/salvage RT vs surgery monotherapy vs radiation monotherapy).…”